Re: internal table

Former Member — Mon, 25 Jun 2007 12:12:42 GMT

Hi,

Go through these notes.

Internal Tables

Internal table

very

important

concept

ABAP/4

programming. For

a novice programmer, it is essential that He

She

understands

the

underlying

concept of

internal table. This

documentation

explains internal table

a very precise and

simple

words.

It explains from the

basics

internal

table and

gradually navigating

its

features

and operations.I

have explained

Standard,

Sorted

and

Hashed

tables

and

its

operations

separately

and

the respective order.My suggestion towards

clear

understanding

internal

table

from

this document

have

clear

idea

Standard

Table first and

practice

and then

move to

Sorted

and Hashed

Tables. For

your

convenience I have isolated

the

system fields

used

for internal

tables

and

defined

few terms

Glossary that

are necessary

for

understanding Internal

Tables. I

would

thank

www.erpgenie.com for providing online

documentation

ABAP/4

for

young

ABAP’ers

like me.

Believe this

document will provide

a clear

understanding of

Internal Table.

Happy

ABAPing.

Introduction:

Internal Tables

are local tables

within a

program containing

series

lines

having same

data

type.

ABAP

Open SQL

allows

single

field, range

fields, entire database table or

view into

Internal table. In

technical terms

Internal table

a dynamic

sequential dataset in which

all records

have

the same

data

structure

and

key. Internal tables

are used

for

fetching

large volume of

data

from

the database, storing

ABAP

working

memory

linebyline

and processing

within

a program.

Although

Internal

tables are declared

with

the

other

data

objects, at

runtime they

behave as

dynamic objects

(i.e.)

need

specify

the size of

the object but only

the length

a row in

internal

table is

fixed. The number

rows

determined

dynamically

at runtime

with

the fixed

structure.

Internal table

characterized by

the

following:

Line Type:

The

line type

may be any data type

another

internal

table. Generally

the data type will be

structure

and each

component

a structure

a column

in this

local table. Key: Key

used

identify

table rows. You

may specify

whether the

key

UNIQUE

NONUNIQUE.

the

name

indicates

UNIQUE

key

cannot contain

duplicate entries

whereas

NONUNIQUE

can.

Table Type:

Table type specifies

the behavior

Internal table while

accessing

the

individual

entries.There are

three types of

table.

Standard

Table defines the

table as

one

that has

the

same

order

its line

type.It

can

be accessed

either by

using

internal

index

or key.The

response

time for

index

access increases

logarithmically

whereas

key

access,it

proportional

to the

number

entries.The key

a standard table is

always

NONUNIQUE.

Standard tables

are

filled using

the

APPEND

statement and

the entries

are

read,modified

and deleted

using

the index

access.

The apt

situation

for

using

standard

table is when

you

need

fill and

process

the

table in separate

steps.

Sorted

Table defines

as the

table that is

sorted

specified order. It can

be accessed

either

using

internal

index

key.

The

response time

for

key increases

logarithmically with the

number

entries. The key

of a

Sorted

table can

be either

UNIQUE or

NONUNIQUE.

Sorted

tables are

filled using

the

INSERT

statement

depending

upon the

UNIQUE

NONUNIQUE

key. The apt situation

when

you

need

table

for

partial sequential processing.

Hashed

Table defines as

the table

that

managed with an

internal has

procedure. It

must be accessed

using

its

hash

key. The response

time

independent

the

number

of entries as

it used

Hash Algorithm. The key

a Hashed

table

must be UNIQUE. Like

Database table, Hashed

table

have

UNIQUE

key. If

the

main operation

the table is

based

the

key

and

for

processing

large

volume of

data,

hashed

table is

the

apt

one.

Creating

Internal Tables:

Internal Tables

can

be declared

as an

abstract data

type

within

a program or

ABAP

data dictionary

and

then

defined

data

object. On

the other

hand

can

directly

defined

as a

data object in

the

program but

it is considered

outdated.

Internal

tables as

data

types:

Internal tables

can

declared

either locally

globally, if

it is

declared

an abstract data

type

within

the

program it is

said

be local

whereas if

ABAP

Data

dictionary

said

global

definition.With

all other

local types

internal

table is declared

using

TYPES

statement.

The

syntax

is as

follows: TYPES

<itab>

TYPE|LIKE

<table

type>

[WITH UNIQUE|NON_UNIQUE

<key>]

[INITIAL

SIZE

<n>]

When

declared

an data

object the TYPE|

is followed

existing data type, but here

you

are

declaring

the

Internal Table as

abstract data

type,

you

must

specify

the table type.

Table

Type:

There

are

two

forms

of table

types, Generic

and

fully

specified.

Generic

Table Types:

There are

two

table

types

namely

INDEX TABLE

and

ANY

TABLE.

INDEX TABLE

&ndash:

For

creating

generic

table

type

for

index

access.

ANY TABLE:

For

creating

fully

generic

table where the

common

operation key

access

only

allowed Data

types

declared

using

Generic type must be

used

for

field

symbols

or interface

parameters

for

routines.

For

data type

if INDEX TABLE

specified only

standard

and

sorted tables

must be passed

the

field

symbols

interface parameters,you

cannot hashed

table.For

a data type

if ANY TABLE

specified

you

can

pass

standard,

sorted

and

hashed

table

the

field

symbols

and

interface

parameters

but the

behavior

all the

table

will be same

(i.e.)

field

symbols

and interface parameters will allow operations that is

common to all tables.

In other

words only

key

access is

allowed, index access

is not

allowed.

Fully

Specified Table

Types: There are

three table

types

as follows:

STANDARD

TABLE

&ndash:

Creates

Standard

Table and

uses

linear

SORTED TABLE:Creates

Sorted

Table

according

the

key

specified and

uses

binary search.

HASHED TABLE

Created

Hashed

Table and

uses

hash

algorithm.

Line

Type:

The

line

type

depends on

TYPE|LIKE

defined.If

TYPE is

used,the

line

type must

take

from

data type either

declared

locally

ABAP

Dictionary. When

internal

table

declared

for

elementary

data types

(C, N, P,

X), default

attributes

are

assigned

when

the

technical attributes

are

not defined

explicitly.

used,

the

data

object mentioned

for

<line

type>

must

recognizable at

that

point.

Key:

The

Key is

specified

follows.

WITH

UNIQUE|NONUNIQUE

KEY

<key>

UNIQUE

specifies

the

mentioned column

cannot contain

any

duplicate

entries

whereas the

NONUNIQUE

specifies the

other way. In

Structured

Line

type

the <coli>

belong

key

its

not

anyway

internal table or

references.

Key

fields can

be Nested Structures

and

are expanded as

the

corresponding

fields

are accessed. The syntax

shown WITH

UNIQUE|NONUNIQUE

KEY

In an elementary line

type

the

entire line

can

be defined

a key.

The

syntax

is as

shown.

WITH

UNIQUE|NONUNIQUE

KEY

TABLE

LINE

addition

the

above

syntax you

can specify the

default

key.

The

default key for a

structured

line type

is a

all

nonnumerical

column

an internal

table,

for

elementary

line type the

default

key

the entire line

and

for an

internal

table whose

line type is

internal

table the

default

key is

empty. WITH UNIQUE|NONUNIQUE

DEFAULT

KEY For

internal table specifying

the key

not

mandatory, if

the key

not

specified

the system defines

arbitrary

key.

Initial

Memory

Requirement:

INITIAL

SIZE <n> With the

above

addition

you

can

specify

the initial

memory

specifying

the

number

lines

internal

table.Often,you cannot

sure of

the

number

lines

internal

they are assigned

dynamically.When using

deep

structures

this

addition will be

really

useful.But

you

can reserve

a initial size of

an internal

table,and

once

its

full,the system allocates

twice as

much

memory

allocated

initially

to 8KB

and

upon

crossing

the

8KB

limit it allocates

12KB each

the

memory

the internal

table.In

order

reserve initial size

and

at the

same

time avoiding

excessive

usage

memory,the

value

<n>

can be

assigned

the quotient

of 8KB

divided by the

length of

line

internal table.

Types: begin

tab,num type I, num1 type I, end

of tab.

Types:

itab

type

standard

table

of tab

with

default

key initial

size

10,sort_itab type

sorted

table

of tab

with

unique

key

num initial

size

10, hash_itab

type

hashed

table of

tab with unique

key

num

initial size 10. The above table

defines

internal

table as

fully

specified data type. All

three internal tables

have

been

initially

allocated 10

lines, but

the way they

access

the individual

entries

different.

‘itab”

is a

standard

table

with

default

key (as

elementary

data type,

the

default

key

is the

entire

line).

‘sort_itab’

internal table that is

sorted

according

the key

‘num’ hash_itab is

internal

table using

hash

algorithm and its

key is

defined as

‘num.

you

use

ANY

TABLE

INDEX TABLE

in the

place of

you

define

Generic Tables that are used

for

passing

Field

Symbols

and

interface

parameters

routines.

Internal

Tables as

Data

Objects:

Internal table can be

declared directly

data

objects

using DATA, STATICS

and

CLASSDATA

statement.

The

STATICS

is used

to create internal

tables

in procedures

and

CLASSDATA is

used

create

internal

tables

classes. The

DATA is used

to declare

internal

table data objects

with

all the

other local objects

in the

program. With

all the

other

data objects

internal

table is

declared

using

the DATA statement with

the

TYPE

addition.

The

syntax

for

both

as follows: DATA:

<itab>

<obj>

[with header line].

The

above

syntax is

used to create

internal table object where

the

addition refers

the existing

table object

within

the

program.

DATA: <itab>

TYPE

<type> [with

header

line].

The

above

syntax is

used to create

internal table object where

the

TYPE

additoin

refers

the

type

defined within

the program

using

the TYPES

statement

type defined

in the

ABAP

Dictionary.

contrast to the

internal table declaration

using

the

TYPES

statement,DATA statement does not

allow

to define

generic internal types. Internal tables

declarations using

the

DATA

statement

must

be fully specified.

Header

Line

Work

Areas:

Header

line

Work

Areas

is one

the

important concepts in Internal tables.As

you see with

the

above

syntax

internal table

declared with the

data

object, header

line.

Both

header

line

and

work

area is

associated data object

with

the

internal

table. They share

the same meaning except that

when

declared

with

the

internal table, is

termed

as header line

otherwise

if declared

separately

termed as

work area.

Before explaining

the

importance of

Header line, let

make clear

how

the

internal

table

accessed. The systems perspective

the

internal

table is

header

the internal

table

and

then body

of the

internal

table. Header

nothing but

single

row of

the internal

table components.

When

a system

processes

the

body

the

internal

table it must

have

accessed

the

header

the

internal table

(i.e.). Work

area or

the

header

line act as

interfaces

the

body of

the

internal

table.

Precisely,when

a system performs a

write

operation on

the

body

the

internal

table, it

first writes

the

header

and

then copy

to the

body

the internal

table

and

applies

the

read

and

other

manipulations. The header of

the internal

table can

be declared

two

ways. One

with

the internal

table

declaration

and

other

declaring

separately

using

the

DATA

statement

shown.

DATA: <itab>

LIKE <obj>

[with

header

line].

The

above

syntax declares

internal table with the

header

line.

you

can

see the

header

line

and

the body

declared

the

statement

and so it

has the

same name.They are differentiated

follows. <itab[]>

addresses

the body

of the

header

line

and <itab>

address

the

header of

the internal

table.

DATA: <itab>

LIKE <obj>, <itab_wa>

LINE

OF <itab>.

The

above

syntax declared

internal

table and

header

line

separately

hence has

different

names. Now a

day its

better to

define the

header

line

separately

order

improve the

performance of

the

program. In

either

case,

each

time the

work area

accessed

the

contents

are

overwritten. This is

the most important

feature

remembered, as

we have

manually

clear

the contents of

the

work area

or the

header

line

at certain

points

the program.

data:itab_obj

type

itab1, itab_obj1 like

itab2

with

header

line,

itab_obj2

like table

mara

with

header

line

‘defined

from

ABAP

Dictionary,tab_obj.

write:

itab_obj1

‘

Header line,

itab_obj1[]

‘Body

[just

writes

the last

row as

its

not

the

loop]

The

above

table creates

internal

table object

from the

type

defined

Table 1. itab_obj

an internal

table

data

object of

itab1

without

header

line.

itab_obj1

internal

table data

object of

itab2

with

header

line. As

mentioned

before, in latter case both

internal table

and

header

line

the same

name. It

differentiated

shown

above.

Processing

Internal Tables: Internal

tables

can

processed

either

as a

whole

individual

lines.

When

internal

table is

processed

on whole

you

address

the

body

the internal table whereas

when internal

table

processed

line by

line you

address

the header

work

area of

the

internal

table.

Note: If

you

are using

internal table

with

header

lines

they

are

processed

separately

because both

the same

name. The body

of the

internal table is

denoted

by <itab>[]

and

header line of

the

internal

table is

denoted

by <itab>. If

the

work

area

header

line

declared

separately, then they

can

process

with

their own

names.

First let us

discuss

the operations

that favor

the

entire

internal

table

processing.

Initializing

Internal

Tables:

There

are

three

statements

initialize the

internal

table with

its

own unique

features. CLEAR <itab>. This statement

clears

the internal

table

and

its

contents

only but

the memory

occupied

not cleared.

The

unique

feature of

this statement is it

can

used

to clear both

the

body

and header of

the internal

table

separately.

To clear

the

body of

the internal table

use <itab>[]

and

clear

the header

the internal

table

use

<itab> as

shown

Table 3. clear : itab_obj1,

‘

clearing

the header

line

the

internal

table

Itab_obj1[]

‘

clearing

the body

the

internal table

REFRESH <itab>.

This

statement

always

the

clear

the body

the

internal

table, header

the internal table cannot

be accessed. As

with

CLEAR statement, the

memory

remains allocated.

refresh

itab_obj1

‘

clearing

the

body

the

internal

table

FREE

<itab>.

This

statement always applies

the

body of

the

internal

table, header

line

cannot be

accessed. But if you

want

really

release

the

memory

allocated

the

internal table this

statement

used. But the

memory

assigned

the header line

remains

allocated.

free itab_obj1

‘

clearing the

body

the

internal

table

Assigning

Internal

tables.

Internal

table

can

be assigned

to another internal table if

they

are

compatible

and

convertible. The entire contents

one

internal

table are assigned

to the

other. When you

are

using

Internal

table

with

header

line

Only

concern

whether

you

are processing

the

body

the

work

area

the

internal table, if it’s

the

body

then

itab[] is

used if

it’s

the

header line then

itab

used.

Internal

tables

can be

assigned

using

the MOVE

statement as with the

other variables.

Alternatively

you

can

use the ‘=’ statement as

follows. MOVE <itab1> TO <itab2>

“

If the

work area

processed

MOVE <itab1>[]

TO <itab2>[]

“

the

body is

processed

MOVE <itab1[]>

TO <itab2>ldquo; This returns

ERROR MOVE

<itab1>

TO <WA>

“

Internal

table header

line

assigned

Alternatively

you

can

use, <itab1> =

<itab2>

“

When

the work

areas

accessed <itab1[]>

<itab2[]>the

body

is accessed

<itab1[]>

= <itab2>

“

Returns ERROR n

=0.

do.

= n +1. move ‘1’

wanum.

move

to wanum1.

move

itab_obj.

append

itab_obj.

while n <=10. move

‘2’

to wanum.

move

‘10’

wanum.

move wa to itab_obj.

append

itab_obj. loop

at itab_obj.

write:/ itab_objnum,

itab_objnum1.

endloop.

Output 111213141516171819110210Now

the

internal

table ‘itab_obj’ has

values as

shown

above.

Alternatively

you

can

use equal

statements

well.

3. Comparing

Internal Tables: Internal

tables can

compared

with

the operands

that are

used

compare other

data

objects. The

most important

criteria

for

comparing

the internal table

are

the

number

lines

they contain.

The

larger

the number

lines, the

larger

it is

for comparisons.

If the

both

the

internal tables

have

same number

lines, then

they

are

compared

line by

line. The

operands

used

for

comparisons are LE, LT,

GE,

GT,

EQ, NE.

Except

for

EQ, the comparison stops

at the

first pair

components

that identifies

the

condition false.

Sorting

Internal Tables: If

you want to

sort

standard

hashed

table using

its table key

(defined at

the time

declaration),

the

following

syntax applies: SORT <itab>

[ASCENDING|

DESCENDING]

[AS TEXT] [STABLE]

the absence

the

table key

field

during declaration

the

default key

the nonnumerical

field of

the table. You

cannot

sort

sorted table, as

they

are

sorted

dynamically

using

the key

specified at

the time

declaration. If

you

want

to sort a

standard

or hashed

table

using

different

key the

following

syntax applies:

SORT <itab>

ASCENDING|DESCENDING]

AS TEXT

[STABLE}

<field1> ASCENDING|DESCENDING]

AS TEXT…. The

above

syntax sorts

the

internal table according

to the

instead

the table

key. ASCENDING|DESCENDING addition:

the

name implies, this

addition

is used

to sort the

fields either

ascending or

descending

order specified. AS TEXT

addition:

This

addition

used

sort

the

strings in alphabetical

order. It

can

used

to sort

the

entire table

or a

single

field

with

the

provision

that

it must be type C. Without

this

addition,

the system

sorts

according

the hardware

platform. STABLE

addition:

you sort a

table

several times

using the

same key, the sort

order

changes

often.

order

have

a stabilized

order

this

addition

used

that

the sort order

does

not change.

sort

itab_obj ‘

sorts

the

itab (from Table 1)

using

table

key in

ascending

(default)

sort

itab_obj

num descending

‘

sorts

itab

using

key

defined

descending order

Sort itab_obj

num1 descending.

Loop

at itab_obj.

Write:/ num1, itab_objnum.

Endloop. Sort

itab_obj

num1

descending.

Loop

itab_obj.

Write:/ itab_objnum1,

itab_objnum.

Endloop.

Sort

itab_obj by

num1

descending

stable. Loop

at itab_obj.

Write:/

itab_objnum1,

itab_objnum.

Endloop. Output

The

first write Statement

outputs

have

taken

only

values) 10

The

second

write

statement

may

output

10 1 9 1 As

you see although

you

sorts

descending

order the

itab_objnum

changes

first and

second

output.

But

with

addition STABLE

you

always

have

the same

order

doesn’t matter

how

many

times

you

sort.

The

third

write

statement with STABLE

10 2 9 1

Operations

for

Index

Tables: The

following

operations

are

allowed

only

for Index

tables

(i.e.)

Standard and

Sorted

Tables. Of

all the

three

tables

listed in this

document, Standard

table

flexible.

As it

does not

allow

UNIQUE key,

there are not

many

constraints

be checked before filling

the table. Hence, it is

advisable to create a

standard

table

and

then

copy to the table of

need.

Appending

Table

lines:

Appending

the table

one

the

quickest

ways

fill the

index

tables.

The

simple form of

Append

follows: APPEND <itab>. When

an internal

declared

with

the

header line,

the

above

statement

moves the

contents

from the

table (defined in <line type>)

the header line

and

then

copied

the

body

the internal table. If

the

Internal

table and

work

area

and

declared

separately

with

the

same <line

type>

then

the

following

syntax applies.

APPEND

<wa> TO <itab>. As

mentioned

before, it is

always

better to declare

work area

and

internal

table separately in

terms

performance.

Appending

Several

Lines

of Internal

Table: APPEND

LINES

<itab1>

[FROM

<n1> TO <n2>]

TO <itab2>

The

above

statement

used

append

the

whole of

<itab1>

<itab2>. Note: Often

during programming, you

might

not realize

what

APPEND

exactly

does. At any

case,

it always

adds

the table thereby keeping

the

existing

entries

the table

not empty.

The

<n1>

and

<n2>

determines the

index

of the

first and

last

lines

<itab1>

to be

copied to

<itab2>. In

the case of

Sorted

table,

the same

applies

except we have to keep

with

the key

defined

during

the

declaration

internal

table.

The

program below shows

two

forms

of append

statement depending

the header line

declaration of

the

internal

table

data

: begin

of struct,

matnr

like maramatnr,ersda

maraersda,

ernam

maraernam,

end

of struct.

types

tab

type

standard

table

struct.

Data:

itab

table

tab

with

header

line, itab1

table

tab,

like line of

itab. select matnr

ersda

ernam from mara into

corresponding

fields

of itab. append itab. endselect. Select matnr

ersda ernam from mara into

corresponding

fields

wa. append

itab.

endselect. Alternatively

you

can

modify

the select without

append and

endselect statement as

shown.

This

statement works

the

same

way

the

above but

better in

performance.select

matnr

ersda ernam from mara appending

fields

of itab. endselect. select

matnr

ersda ernam

from

mara appending

fields

of table itab.

Inserting Table

lines: The

INSERT

statement allows

you to

insert lines

the

Index

tables. This

command

opt for Sorted

table. Though

can

use this

command

for

standard

table, APPEND

considered

be the

best

terms

of performance. Like

APPEND,

you can

insert

either a

single

line

or multiple

lines

the

table. To

insert

single

line

the

following

syntax

applies:

INSERT

<line>

INTO <itab>

[INDEX <index>]

The

<line>

can

a work

area that is

either

compatible

convertible

the

<line type> declared

with

the internal

table.

Without

the

INDEX addition,

this

statement is

allowed

only within

a loop

that

it inserts

the lines to internal

table

thereby

incrementing

index

automatically. With the

INDEX addition,

the

internal

table is

filled

before

the line specified

<index>

and

the

following line’s

index

incremented

one. When

the

total number of

lines

an internal

table

equal to <index> 1,

the

<line>

inserted

at the

end

the

local

table. If

table

has

less than

<index>

lines, SYSUBRC

set

4. Inserting

several

lines: The

following

syntax

applies

when

you

want

insert several

lines

from one

internal

table to

the

other

specifying

the <index>. INSERT

LINES

OF <itab1>

INTO <itab2>

[INDEX <index>]

The

above

statement inserts

the lines from <itab1>

to <itab2> line

line

like the above INSERT

statement. INSERT LINES

OF <itab1>

[FROM

<n1>

TO <n2>]

INTO <itab2>

[INDEX

<index>] The above statement specifies

<n1>

and

<n2>

thereby

the first

and

last lines of

<itab1>

<itab2>.

Data : begin

of struct,

Empno

type I

Empname(50)

type

char, End

of struct.

Types

tab

type

sorted

table of

struct with

unique

key

empno Data

itab like

tab

with

header

line,

Jtab

tab

with

header

line, structempno

‘0001’.

structempname

‘Stephen’.

Insert

struct into

itab. structempno

‘0002’.

structempname

‘Jack’.

Insert

struct

into

itab. structempno

‘0003’.

structempname

‘Jill’.

Insert

struct

into

itab. Loop

at itab. Write:/ itabempno,

itabempname.

Endloop.

Output

0001

Stephen

0002

Jack

0003

Jill

Insert

lines

itab

into

jtab.

Loop

at jtab.

Write:/ jtabempno,

jtabempname.

Endloop.

Output 0001

Stephen

0002 Jack 0003

Jill The

above

program shows

the

demonstration

both

the insert statements

for

a sorted

table

with

unique

key. 3.

Reading

Lines

using the

Index.

In addition

inserting,

lines

from the local

tables

can

read

using READ statement. The syntax

follows.

READ TABLE <itab>

INDEX <index>

<result>. The

system

reads the

line

with

the <index> from the

table

<itab>. Read

table itab

index

into

struct. Write:/ structempno,

structempname.

Output 0002

Jack

The above

program

reads

single

entry from internal

table (itab)

with

index

2. 4. Changing

Lines:

You

can

change a

single

line

group

of lines using

the

MODIFY

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To change

single

line

of the

local table without

the condition the

following

syntax

is used. MODIFY <itab> from <wa>

The

<wa>

must be compatible with

the

<line

type>

defined

(declared

with

the

internal

table). It

searches

for

the contents

the

internal

table whose

table

key

values

correspond

the

values

<wa>

and then

the

table

modified. To

change one

more lines that meet

certain

condition

the following

syntax

used. MODIFY <itab>

from <wa>

TRANSPORTING

<f1>…<fn> WHERE

<cond>

The <wa> must

compatible

with

the <line type>

defined

(declared

with

the

internal

table). It

searches

for

the contents

changed and

contains

the new contents

well. All the

lines

of the

internal

table that satisfies the

condition

changed. Structempno

‘0003’.

Structempname

‘Jason’ Modify itab form struct. Modify

itab from

struct transporting

empname

where

(empno

‘0003’).

‘

This

the

alternative

way

modify, but

it changes

several lines

exist. Loop at

itab. Write:/

itabempno,

itabempname.

Endloop Output

0001

Stephen 0002

Jack

0003

Jason

The

above

program demonstrates

the use

of MODIFY Statement.

‘struct’

compatible

with

the

internal

table (itab)

line

type, the

internal

table is

searched

for

the

entries

that

are

compatible

with

the work

area and

they

are

modified. Deleting

Lines

from Internal

Table: To

delete single

more lines from the

internal table using

index

use DELETE

statement. To

delete

line

using

the

index

the

syntax

follows: DELETE

ITAB

[INDEX <index>]

The

above

statement deletes

the line from

the internal

table

<itab>

that

corresponds

to the

INDEX <index> and

reduces

the

subsequent

lines

Without the

INDEX option

can be

only

used within

the loop

and

the

manipulation is

carried

implicitly

using SYTABIX.

delete more lines using

the

index

the

syntax

as follows: DELETE

ITAB [FROM

<n1>

TO <n2>]

WHERE

<cond>

The

above

statement deletes

all

the

lines

from index <n1>

<n2>

that

satisfies

the

condition. If

you

not

specify

FROM

<n1>

the system deletes

from the first

line

till <n2>. Likely

If you

not specify

<n2>

the

system

deletes all lines

from <n1>

till the end

the

table. Do

N =

+1. Itab_obj1num

Itab_obj1num1

Append itab_obj1.

While n<=5. Loop at

itab_obj1.

Write:/

itab_obj1num,

itab_obj1num1.

Endloop. Output

10 3 10

Delete

itab

index

Delete

itab

from 1

where

num <

2. B

The statement

deletes

the second

entry

from

top of

the internal

table. The

statement

B deletes

the

entries

from index

index

where

the first field

is less

than

(i.e.)

the

first entry

of the

internal table. LOOP

Operations

using INDEX.

You

can

process

an internal within

a loop

using

the

index.

The

syntax

is as

follows. LOOP

<itab>

[FROM

<n1>

<n2>]

[WHERE <cond>]

ENDLOOP

The

above

statement loops

the internal table

from index

<n1>

index

<n2>

that satisfies

the

condition

<cond> and

then

processed. The loop

statement

can be

executed

even

without

the

additions, except

that whole internal table

processed, but

it’s

advised

that

wherever

you

meet

conditions,

its

better

specify

in order

improve

the

performance. Operation

for

ANY TABLE:

The

operation

listed

applies

any table

type,

but

you know the

table

type

its

better

use

the apt command

for

that table

type. For

instance,

you

can

append lines in a

standard

table using

both

APPEND and

INSERT

command,

but

APPEND

preferred

INSERT for performance

reasons. The following

shows

the

operations for any

tables. The most important

thing

these

operations

is,

work for any

type

table; you

must use

the operations

that

are

common (i.e.)

you

must

specify

the

key

but not

the index. 4.

Inserting

Table lines:

The

INSERT

statement allows

you

insert

lines

the Index

tables.

This

command

opt for Sorted

table.

Though

can

use this

command

for

standard

table, APPEND

considered

be the

best

terms

performance.

APPEND, you

can

insert either

a single

line or

multiple

lines

to the

table. To insert

a single line to the

following syntax

http://erpgenie.com/abaptips

Powered

by Joomla for

ERPGenie.COM!

Generated: 20

April, 2007,

01:21

ERPGenie.COM

ABAP Tips and

Tricks

Database

applies:

INSERT

<line>

INTO TABLE

<itab>

The

<line> can

work area

that

either

compatible

or convertible to

the

declared

with

the internal table. Inserting

several

lines:

The

following

syntax

applies when

you

want to

insert several

lines

from one

internal table to

the other

specifying

the

<index>. INSERT

LINES OF <itab1>

INTO

TABLE

<itab2>

The

above

statement inserts

the lines from

<itab1>

<itab2>

line

the above INSERT

statement. INSERT

LINES

OF <itab1>

[FROM

<n1> TO <n2>]

INTO TABLE

<itab2>

The

above

statement specifies

<n1>

and

<n2>

thereby

the first

and

last lines of

<itab1>

<itab2>.

As you

can

see the

INSERT

statement of Index

Table and

for

All Tables

differs

the

keyword

TABLE.

Generally,

for

All tables

you need to include

the

TABLE

keyword

most of

the statements. If

it’s

Standard

table, the

line is

appended

the

end of

the internal table, if

its

sorted

table, the line

inserted according

the

table

key

and

for

Hashed

table, the

line

inserted

according

the hash

algorithm. Data

: begin

of struct,

Empno

type I

Empname(50)

type

char, End

of struct.

Types

tab

sorted

table

struct

with

unique

key

empno

Data

: itab

tab

with

header

line, Jtab like

tab

with

header

line,

structempno

‘0001’. structempname

‘Stephen’.

Insert

struct into

table itab.

Struct

empno

= ‘0002’.

structempname

‘Jack’.

Insert

struct into

table itab. structempno

‘0003’.

Structempname

‘Jill’.

Insert

struct into

table

itab.

Loop

at itab.

Write:/

itab

empno, itabempname.

Endloop.

Output 0001

Stephen

0002

Jack

0003

Jill

Insert

lines

itab

into

table

jtab. Loop at

jtab. Write:/ jtabempno,

jtabempname.

Endloop. Output

0001

Stephen

0002

Jack

0003

Jill

The

above

program shows

the demonstration

of both

the insert

statements

for

a sorted

table with

unique key.

It is same

as example

demonstrated

for

INSERT

statement for

INDEX tables.

order

differentiate

that

only ‘TABLE’

key is

included in

INSERT

statement for

ALL

TABLES operations, I

have

given

the

same

example. Changing

Lines:

You

can

change a

single

line

group

of lines using

the

MODIFY

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To change

single

line

of the

local table without

the condition the

following

syntax

is used. MODIFY TABLE

The

<wa>

must

be compatible with the

<line

type>

defined (declared

with

the internal

table). It searches

for

the

contents

the

internal

table

whose table key

values

correspond

the values

<wa>

and

then the

table is modified. To change

one

lines

that

meet certain

condition the

following

syntax

used.

MODIFY TABLE <itab>

from <wa>

TRANSPORTING <f1>…<fn>

WHERE

<cond>

The

<wa>

must be compatible with

the

<line

type>

defined

(declared

with

the internal

table). It searches

for

the

contents

changed

and contains

the

new contents

well. All

the

lines

the internal

table

that

satisfies

the condition is

changed.

Structempno

‘0003’.

Struct

empname

‘Jason’

Modify table itab form struct.

Modify

table itab

from struct transporting

empname

where

(empno

‘0003’).

‘

This

the

alternative way

to modify, but it changes several lines

exist.

Loop

at itab.

Write:/ itabempno,

itabempname.

Endloop

Output 0001

Stephen 0002

Jack

0003

Jason

The

above

program demonstrates the

use of

MODIFY

Statement.

As ‘struct’ is

compatible

with

the

internal

table

(itab)

line type, the internal

table

searched

for

the entries that are compatible with the

work area

and

they are modified.

It is same

as example

demonstrated

for

INSERT

statement

for

INDEX tables. In

order

differentiate that only

‘TABLE’

key

included

INSERT statement

for

ALL

TABLES

operations,

have

given

the

same

example. Deleting

Lines: You

can

delete

single

line

or group

lines

using

DELETE

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To delete

a single

entry of

the internal

table

using

the

table key,

one of

the following

syntax

is used. DELETE TABLE <itab>

FROM

<wa>

The

above

statement deletes

single

entry

from the

internal table

using

the corresponding

table

key

from <wa>. The

<wa>

must

be compatible with the

line

type of

<itab>. DELETE

TABLE

<itab>

WITH

TABLE

KEY

<k1>

<fn> The above

statement is

exactly the

same

but you

have

explicitly

define

the table key

fields.

To delete a group

lines

of the

internal table that

meets

certain

condition, the

following syntax

used.

DELETE TABLE <itab>

WHERE

<cond> To

delete the

adjacent

duplicate

entries

the

following

syntax

is used.

DELETE ADJACENT DUPLICATE ENTRIES

FROM

<itab>

COMPARING <f1>…<fn>

[ALL

FIELDS].

In order

to execute this

statement

successfully,

we have to give the

following

options:

you

give

the COMPARING <f1>…<fn>,the

fields

<f1>

till <fn>

are compared

with

all

the lines of

the table, if

it founds

identical entries, they

are

deleted.If you

give ALL

FIELDS,

all the

fields of

the internal table

compared

and

upon

finding

identical

entries,

they

are

deleted.By omitting both

the options,

the

key

fields of

the internal table

are

compared

and

upon

finding

identical

entries,

they

are

deleted. Move

‘1’

wanum.

Move

‘10’

wanum1.

Append

itab_obj. Loop at

itab_obj. Write:/ itab_objnum,

itab_objnum1.

Endloop.

Output

111213141516171819110

1 10

10wanum

wanum=

delete table

itab

from wa.‘

This

statement

deletes

the content

itab

that

corresponds

delete adjacent

duplicate

entries

itab_obj

comparing

all fields

‘A

delete adjacent

duplicate

entries

from

itab_B

The statement A

deletes

the entries where all the

fields

are identical in adjacent

rows, (i.e.)

[1 10 &

10]

The

statement B

deleted

all the

entries

that

have

identical values in the

first field, (i.e.) [Internal Table

itab_obj

contains only

10]

Reading

lines: To

read

single

entry

an internal table

any

table type

use

the

following statement. READ TABLE <itab>

<key>

explained

above

in order

to be

valid

statement

for

any

type of

table,

you

must use

the <key>

not the

<index>

that

you use

for

INDEX tables.

The

key you

specify

can be

either

table

key

user defined

key. First

lets

look at

table

key. When

you

don’t

want specify

all the table keys

explicitly you

can use

the

following

statement. READ

TABLE

<itab>

FROM <wa>.

Alternatively

you

can

specify

the table keys expicitly in the

READ

statement

follows:

READ

TABLE

<itab>

WITH

TABLE

KEY

<k1>

= <fn>. If

you

want

specify

different

key other

than

table

key,

you

can use

the following

statement. READ

TABLE

<itab>

WITH

KEY <k1>

<f1>

…. <kn>

<fn>. When you

compare both

the

READ

Statements, you can easily

trace out, ‘TABLE’

keyword

is missing.

The

following

program demonstrates

the use

of all the READ

statements.Structempno

‘0001’.

Read

table itab

from struct. Write:/ structempno,

structempname.

Output

0001

Stephen read

table

itab

with

table

key

empno

‘0002’

write:/ itabempno,

itabempname.

Output

0002

Jack

read

table itab

with

key

empname

‘Jason’.

Write:/ itabempno,

itabempname

Output

0003

Jason

The first

output

reads

from the internal

table

using

the table key

from the work

area. The only

requirement

work area

must be compatible with

the

line

type

the

internal

table. The

second output reads

from the internal table

with

the

table key

defined

explicitly. The third

output

reads from the

internal

table using

a different

key

defined

explicitly

but

not

the

table key. There is

complicate

form

of READ statement where

you can

retrieve

from

the internal table

comparing

the fields

the

work

area and

internal table and

transporting the

required

fields in to

the same

work area.

Here

you can

see

that

same work

area is

used

check

the

entries

against the

internal table and

used

for

output

as well. The statement uses

the following

syntax.

READ

TABLE

<itab>

[COMPARING

<f1>…<fn> ALL

FIELDS]

FIELDS |

NO FIELDS]

you

can

see

both

the

comparing

and transporting

are

optional and

then

it behaves

normal read statement.

The

work

area must be

compatible

with

line

type

the internal

table.

Structempno

‘0003’.

Read table itab struct into

struct

comparing

empno

transporting

empname

Write:/ structempno,

struct

empname

Output 0003

Jason

The above

statement is

not

necessary

for

this table but

just for understanding

the READ

concept. The

work

area is

filled

with

‘0003’

and

the

statement

reads the

internal table by

comparing

the

corresponding

entry in the work

area and

then

the

‘empname’

field

transported to the work

area. Processing

Table

Entries

Loops.

Loop

statements

are used

process

the

entries

the Internal

Table. There are lots

options

order

process

the required

entries

the

loop.

The

syntax

is as

follows:

LOOP AT <itab>

[INTO <wa>]

[WHERE

<cond>]

ENDLOOP. As

you

can

see the

INTO <wa>

and

WHERE <cond>

are optional.

If you

use the

loop

without

any

options,

all the entries

onebyone

are

processed

from the

internal

table. The

<wa>

must

be compatible with the

line

type of

the

internal

table. Generally, the INTO <wa> is

used when

the

internal

table is declared

without

the

header

line.

But

performance wise, it

better to

declare the internal table without

the

header

line

and

declare a

separate work

area that is

compatible with

the

line

type

of the

internal table.WHERE

<cond>

option

used

avoid

processing

all the

entries

the internal

table.

Hence

the internal

table contents

that

satisfies

the condition will enter the loop

and

further they

are processed

according

the requirements. LOOP

<itab>

TRANSPORTING NO FIELDS WHERE

<cond>

the

statement indicates, none

the

internal table fields

are

transported

in to the

loop,

even

the entries

that satisfy

the

condition. But this

statement

used

at the

high

end

where you

want

to find

the

number

of lines of

internal table

that satisfies

certain

condition.

The

following

program explains

each

the

statements

above

clearly,

Data : begin

struct Roll_no type

Name(50)

type

c, Mark1 type

I,type

I, End

of struct.

Data

: itab

standard

table

struct,

line of

itab, Itab1

like sorted

table of

with

header

line, N

type I. Waroll_

no =

‘121’.

Wa –name

‘Wilson’.

–mark1

‘80’.

–mark2

‘85’

Append

itab.

Waroll_

‘122’.

Wa –name

‘William’.

mark1

‘82’.

Wa mark2

‘45’

Append

wa to itab.

Waroll_

‘123’.

Wa name

‘Thomson’.Wa mark1

‘76’.

mark2

‘54’ Append

itab. Waroll_

‘124’.

Wa name

‘Daniel’.

mark1

‘87’.

mark2

‘54’

Append

wa to itab.

Insert

lines

of itab

from

itab1.

Loop

at itab

into

wa. Write:/

waroll_

no,waname,

wamark1,

wamark2.

Endloop,

Output 121

Wilson 80

122

William

123 Thomson

54 124

Daniel

Loop

itab1.

Write:/

itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endloop.Output

121

Wilson 80 85

122

William

123 Thomson

124 Daniel

54 Loop at

itab

into

where

roll_no

= ‘124’.

Write:/ waname,

wamark1,

wamark2.

Endloop.

Output

124

Daniel 87 54

Loop

at itab1

where

roll_no

‘123’.

Write:/

itab1name,

itab1mark1,

itab1mark2.

Endloop. Output

123

Thomson

loop

at itab1

transporting

no fields

where

mark2

‘54’. N

+1 ‘ Initialize

0. endloop.

Output 2

Control Level Processing

Control

Level

Processing

internal

table means

that you can divide the

internal

table into

different

groups

based on

certain

fields.

A very

important

aspect of

the control

level processing

sorting

the

internal

table. The first field

the

internal table

has

the highest

control

level and

on.

Therefore when

you

declare the

internal

table the

control

levels

of all the fields

must

be known.

Once

you

declare the

internal

table defining

the

correct control

levels

for the

fields the

internal

table is

sorted

by the

first field, second

field

and

on.

The control

level

statement

has

structure

with

and

ENDAT

with

the control

levels. The syntax

shown.

<level>

<Statements> ENDAT. There

are 4

levels

defined with the

statement. FIRST

–

First Line of

the internal

table

LAST

–

Last Line of

the internal table. NEW <field> Beginning

group

entries

that has

the same contents

<field>

and

the left of

<field>

END OF

<field>

Ending

group

entries

that has

the

same

contents

as <field>

and

to the

left of <field>

control level statements

are

allowed

within

the

loop

make

optimum use

this

feature. The

program below

demonstrates

the use

of the

control

levels. Loop

at itab1. At

first

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat. Loop

at itab1. At last

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat. Loop

at itab1.

new mark2

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat.Loop at

itab1. At end

mark2

Write:/ itab1roll_

no, itab1name,

itab1mark1,

itab1mark2.

Endat.

Output 121

Wilson

80 85

124

Daniel 87

123

Thomson

124

Daniel 87

Creating Summarized

Internal

Tables:

create a summate

entries

an Internal table COLLECT

statement is

used. The

syntax

is as

follows:

COLLECT

<wa>

INTO <itab> The <wa>

must compatible

with

the

line type of

<itab>. This creates

sum of

all numerical

fields

in the

internal table if

the system finds

corresponding

entry

of table key

fields

between

<wa>

and

the

table. If

fails

find

an entry, the

statement behaves

like a

normal INSERT statement. The

only

prerequisite

create

summarized

internal

table is

that all the fields

that

are

not part of

the

table

key must be

numerical columns.

Determining

the Attributes

Internal Table:

This

sounds

bit strange

we are

defining

the

attributes

the internal table, then

why

need

statement

find

the attributes.

The

internal table we

declare is

static

definition

but

during

runtime it gets dynamically

assigned.

determine

the

attributes use

the following

statement. DESCRIBE

TABLE

<itab>

[LINES

<l>]

[OCCURS <n>]

[KIND <k>]

The

LINES return the

number

lines

the internal

table.

OCCURS

returns

the

value

of the

INTIAL

SIZE

the

internal

table

and

KIND

returns the

table type

of the

internal table ‘T’

for

standard

table, ‘S’

for

sorted table and

‘H’

for

Hashed table.

Exception of

Internal

Table:

APPEND

statement

used

create

Ranked

List for

standard

tables. In

order

create

Ranked

List,

declare the

internal

table and

use the

following statement. APPEND <wa>

<itab>

SORTED

by <f>. After this

statement, the

contents

are not

appended

the

last line of

the internal table

but

gets

sorted

and

inserted

in the

respective

order. The main

feature of

this statement

that it violates

that

internal

table are dynamic datasets

follows.

The

contents

<wa>

are inserted in to

<itab>

long

the

number

of lines of

internal table does not

exceed

<n>

(declared

INTIAL

SIZE). When

it exceeds the

line

discarded

thereby

defining

static declaration

internal table.

Tips

Tricks:

The number

internal

tables

in a

program must

kept

minimum

possibleIf

you

are creating

internal of

standard

type

and

going to

process

small amount

of data its

better

declare

internal

table directly using

DATA statement.Try to

avoid

using

internal

table

with

header

line; declare a

separate work

area compatible to

the internal table

line type.Always try

to use

the

system

fields

when you

processing the

internal

table entries within

the

loop.APPEND

statement

always

adds to the

last

line

the

internal

table whereas

MODIFY changes entry

that is

already

the

table.If you

are

using

internal

table within

loop that behaves

differently

at each

pass

make sure that you

have

cleared

the header

line

or work

area.If

you don’t know the

exact value or

don’t

know

the variable

till runtime

you can

address

those

values using

‘<variablename>&

rsquo;.Use the

appropriate

statements

for

Standard,

Sorted

and

Hashed

Tables

System

Fields

for

Internal Tables: SYSUBRC

–

This

common

all

the

statements

ABAP. This

system

field

is set to

when the

statement

executed

successfully

else

it is

set

to 4.

SYTABIX

–

This

system field

contain

the current

line

internal

table. The

internal

table must of

either

Standard

Sorted

table.

For

Hashed

table this

field

is not

set. As

this field is

set only

for

Index

tables

SYTABIX

set to

the index for the

following

operations. APPEND: APPEND

sets

SYTABIX

to the

total

number

entries

the internal

table

(I.e.)

index

the

last line of

the

internal

table.

COLLECT: COLLECT

sets

SYTABIX

to the

index

of the

existing

inserted line of

the

internal table. LOOP

AT: When the

internal

table enters

loop, SYTABIX

contains

the

index

of the

line

that enters loop

and

when

it exits

loop

SYTABIX

reset

the index

that it had

before

entering loop.

READ: SYTABIX

set to

the index of

the line

the

internal

table that

read. The operations

DESCRIBE, LOOP

and

READ TABLE sets

the

following

system fields

follows.

SYTFILL

– contains

the

number

of lines in the internal table

SYTLENG

–

contains

the length

the

lines

the internal

table SYTOCCU

–

contains

the initial

amount

memory

allocated to the

internal table. Glossary:

Data Object

Instance

Data type. It occupies a

field

memory

Data Type Describe

the

technical attributes

of a

Data

Object

Flat

Structure

containing

only

elementary data types Hashed

Table One type

an internal table

where

it is

accessed

using hash

algorithm and

hash

key. In

contrast

Standard and

Sorted

tables, searching

time

does

not

increase

with

the size of

the table. Header

Line It’s

a work

area

internal

table that acts

interface

the

table.

Index

Table:

Index

table uses

linear

and

index

access

the

table. It access

time

increases with the

size

of the

table

Internal

Tables

A Data Object (either declared

directly or

declared

from the

Data Type)

that

stores the

data

and

process

within

the program.

You

can

define

three

types

namely, Standard,

Sorted

and

Hashed

Table. Sorted

Table

An Internal

table

type

that is

sorted with its

specified key

Standard Table

An internal

table

that

unsorted

Internal Tables

Internal table

very

important

concept

ABAP/4

programming. For

a novice programmer, it is essential that He

She

understands

the

underlying

concept of

internal table. This

documentation

explains internal table

a very precise and

simple

words.

It explains from the

basics

internal

table and

gradually navigating

its

features

and operations.I

have explained

Standard,

Sorted

and

Hashed

tables

and

its

operations

separately

and

the respective order.My suggestion towards

clear

understanding

internal

table

from

this document

have

clear

idea

Standard

Table first and

practice

and then

move to

Sorted

and Hashed

Tables. For

your

convenience I have isolated

the

system fields

used

for internal

tables

and

defined

few terms

Glossary that

are necessary

for

understanding Internal

Tables. I

would

thank

www.erpgenie.com for providing online

documentation

ABAP/4

for

young

ABAP’ers

like me.

Believe this

document will provide

a clear

understanding of

Internal Table.

Happy

ABAPing.

Introduction:

Internal

Tables

are local tables

within a

program containing

series

lines

having same

data

type.

ABAP

Open SQL

allows

single

field, range

fields, entire database table or

view into

Internal table. In

technical terms

Internal table

a dynamic

sequential dataset in which

all records

have

the same

data

structure

and

key. Internal tables

are used

for

fetching

large volume of

data

from

the database, storing

ABAP

working

memory

linebyline

and processing

within

a program.

Although

Internal

tables are declared

with

the

other

data

objects, at

runtime they

behave as

dynamic objects

(i.e.)

need

specify

the size of

the object but only

the length

a row in

internal

table is

fixed. The number

rows

determined

dynamically

at runtime

with

the fixed

structure.

Internal table

characterized by

the

following:

Line Type:

The

line type may be

any

data type or

another

internal

table. Generally

the data type will be

structure

and each

component

a structure

a column

in this

local table. Key: Key

used

identify

table rows. You

may specify

whether the

key

UNIQUE

NONUNIQUE.

the

name

indicates

UNIQUE

key

cannot contain

duplicate entries

whereas

NONUNIQUE

can.

Table Type:

Table

type specifies

the behavior

Internal table

while

accessing the

individual

entries.

There

are

three types

table.

Standard Table

defines

the table as

one

that has

the same order

its line

type.It can

be accessed

either

using

internal

index

key. The response

time

for

index

access

increases

logarithmically

whereas

key access, it is proportional

the number of

entries.The

key

a standard table is

always

NONUNIQUE.

Standard

tables

are filled

using the

APPEND statement

and

the

entries

are read,modified

and

deleted using the

index

access.

The apt

situation

for using

standard

table

when

you

need

fill and

process

the

table in separate

steps.

Sorted

Table defines

as the

table that is

sorted

a specified

order.

can be

accessed

either

using

internal index

key.

The

response

time for key

increases

logarithmically

with

the

number

of entries. The key

Sorted

table

can

be either

UNIQUE

NONUNIQUE.

Sorted

tables are filled

using

the INSERT

statement depending upon

the

UNIQUE

NONUNIQUE

key. The apt

situation

when you

need

a table for partial sequential

processing.

Hashed Table

defines

the

table

that

managed with an

internal

has

procedure.

It must be

accessed using

its

hash key.

The

response

time is

independent

the number

entries

used

Hash

Algorithm.

The

key

a Hashed table must

UNIQUE.

Like Database

table,

Hashed

table have a

UNIQUE

key. If

the main

operation

in the

table is based

the key

and

for

processing

large

volume of

data,

hashed table is

the apt one.

Creating Internal

Tables:

Internal Tables

can

be declared

as an

abstract data

type

within

a program or

ABAP

data dictionary

and

then

defined

data

object. On

the other

hand

can

directly

defined

as a

data object in

the

program but

it is considered

outdated.

Internal tables

data types:

Internal tables

can

declared

either locally

globally, if

it is

declared

an abstract data

type

within

the

program it is

said

be local

whereas if

ABAP

Data

dictionary

said

global

definition.With

all other

local types

internal

table is declared

using

TYPES

statement.

The

syntax

is as

follows: TYPES

<itab>

TYPE|LIKE

<table

type>

[WITH UNIQUE|NON_UNIQUE

<key>]

[INITIAL

SIZE

<n>]

When

declared

an data

object the TYPE|

is followed

existing data type, but here

you

are

declaring

the

Internal Table as

abstract data

type,

you

must

specify

the table type.

Table

Type:

There

are

two

forms

of table

types, Generic

and

fully

specified.

Generic Table Types:

There are

two

table

types

namely

INDEX TABLE

and

ANY

TABLE.

INDEX TABLE

&ndash:

For

creating

generic

table

type

for

index

access.

ANY TABLE

For

creating

fully

generic

table where the

common

operation key

access

only

allowed Data

types

declared

using

Generic type must be

used

for

field

symbols

or interface

parameters

for

routines.

For

data type

if INDEX TABLE

specified only

standard

and

sorted tables

must be passed

the

field

symbols

interface parameters,you

cannot hashed

table.For

a data type

if ANY TABLE

specified

you

can

pass

standard,

sorted

and

hashed

table

the

field

symbols

and

interface

parameters

but the

behavior

all the

table

will be same

(i.e.)

field

symbols

and interface parameters will allow operations that is

common to all tables.

In other

words only

key

access is

allowed, index access

is not

allowed.

Fully

Specified Table

Types: There are

three table

types

as follows:

STANDARD

TABLE

&ndash:

Creates

Standard Table

and

uses

linear

SORTED TABLE:Creates

Sorted

Table

according

to the

key

specified and

uses

binary search.

HASHED

TABLE

Created

Hashed

Table and

uses

hash

algorithm.

Line

Type:

The

line

type depends

TYPE|LIKE

defined.If

TYPE is

used,the

line

type must

take

from

data type either

declared

locally

ABAP

Dictionary. When

internal

table

declared

for

elementary

data types

(C, N, P,

X), default

attributes

are

assigned

when

the

technical attributes

are

not defined

explicitly.

used,

the

data

object mentioned

for

<line

type>

must

recognizable at

that

point.

Key: The

Key is

specified as

follows. WITH

UNIQUE|NONUNIQUE

KEY

<key>

UNIQUE

specifies

the

mentioned column

cannot contain

any

duplicate

entries

whereas the

NONUNIQUE

specifies the

other way. In

Structured

Line

type

the <coli>

belong

key

its

not

anyway

internal table or

references.

Key

fields can

be Nested Structures

and

are expanded as

the

corresponding

fields

are accessed. The syntax

shown WITH

UNIQUE|NONUNIQUE

KEY

In an elementary line

type

the

entire line

can

be defined

a key.

The

syntax

is as

shown.

WITH

UNIQUE|NONUNIQUE

KEY

TABLE

LINE

addition

the

above

syntax you

can specify the

default

key.

The

default key for a

structured

line type

is a

all

nonnumerical

column

an internal

table,

for

elementary

line type the

default

key

the entire line

and

for an

internal

table whose

line type is

internal

table the

default

key is

empty. WITH UNIQUE|NONUNIQUE

DEFAULT

KEY For

internal table specifying

the key

not

mandatory, if

the key

not

specified

the system defines

arbitrary

key.

Initial Memory

Requirement: INITIAL

SIZE

<n>

With

the above

addition

you

can

specify the

initial memory by

specifying

the

number

lines

an internal

table.Often,you

cannot

be sure

the

number

lines

an internal

they

are

assigned

dynamically.When using

deep

structures

this

addition will be

really

useful.But

you

can reserve

a initial size of

an internal

table,and

once

its

full,the system allocates

twice as

much

memory

allocated

initially

to 8KB

and

upon

crossing

the

8KB

limit it allocates

12KB each

the

memory

the internal

table.In

order

reserve initial size

and

at the

same

time avoiding

excessive

usage

memory,the

value

<n>

can be

assigned

the quotient

of 8KB

divided by the

length of

line

internal table.

Types: begin

tab,num type I, num1 type I, end

of tab.

Types:

itab

type

standard

table

of tab

with

default

key initial

size

10,sort_itab type

sorted

table

of tab

with

unique

key

num initial

size

10, hash_itab

type

hashed

table of

tab with unique

key

num

initial size 10. The above table

defines

internal

table as

fully

specified data type. All

three internal tables

have

been

initially

allocated 10

lines, but

the way they

access

the individual

entries

different.

‘itab”

is a

standard

table

with

default

key (as

elementary

data type,

the

default

key

is the

entire

line).

‘sort_itab’

internal table that is

sorted

according

the key

‘num’ hash_itab is

internal

table using

hash

algorithm and its

key is

defined as

‘num.

you

use

ANY

TABLE

INDEX TABLE

in the

place of

you

define

Generic Tables that are used

for

passing

Field

Symbols

and

interface

parameters

routines.

Internal Tables

Data

Objects:

Internal table can be

declared directly

data

objects

using DATA, STATICS

and

CLASSDATA

statement.

The

STATICS

is used

to create internal

tables

in procedures

and

CLASSDATA is

used

create

internal

tables

classes. The

DATA is used

to declare

internal

table data objects

with

all the

other local objects

in the

program. With

all the

other

data objects

internal

table is

declared

using

the DATA statement with

the

TYPE

addition.

The

syntax

for

both

as follows: DATA:

<itab>

<obj>

[with header line].

The

above

syntax is

used to create

internal table object where

the

addition refers

the existing

table object

within

the

program.

DATA: <itab>

TYPE

<type> [with

header

line].

The

above

syntax is

used to create

internal table object where

the

TYPE

additoin

refers

the

type

defined within

the program

using

the TYPES

statement

type defined

in the

ABAP

Dictionary.

contrast to the

internal table declaration

using

the

TYPES

statement,DATA statement does not

allow

to define

generic internal types. Internal tables

declarations using

the

DATA

statement

must

be fully specified.

Header

Line

Work

Areas:

Header

line

Work

Areas

is one

the

important concepts in Internal tables.As

you see with

the

above

syntax

internal table

declared with the

data

object, header

line.

Both

header

line

and

work

area is

associated data object

with

the

internal

table. They share

the same meaning except that

when

declared

with

the

internal table, is

termed

as header line

otherwise

if declared

separately

termed as

work area.

Before explaining

the

importance of

Header line, let

make clear

how

the

internal

table

accessed. The systems perspective

the

internal

table is

header

the internal

table

and

then body

of the

internal

table. Header

nothing but

single

row of

the internal

table components.

When

a system

processes

the

body

the

internal

table it must

have

accessed

the

header

the

internal table

(i.e.). Work

area or

the

header

line act as

interfaces

the

body of

the

internal

table.

Precisely,when

a system performs a

write

operation on

the

body

the

internal

table, it

first writes

the

header

and

then copy

to the

body

the internal

table

and

applies

the

read

and

other

manipulations. The header of

the internal

table can

be declared

two

ways. One

with

the internal

table

declaration

and

other

declaring

separately

using

the

DATA

statement

shown.

DATA: <itab>

LIKE <obj>

[with

header

line].

The

above

syntax declares

internal table with the

header

line.

you

can

see the

header

line

and

the body

declared

the

statement

and so it

has the

same name.They are differentiated

follows. <itab[]>

addresses

the body

of the

header

line

and <itab>

address

the

header of

the internal

table.

DATA: <itab>

LIKE <obj>, <itab_wa>

LINE

OF <itab>.

The

above

syntax declared

internal

table and

header

line

separately

hence has

different

names. Now a

day its

better to

define the

header

line

separately

order

improve the

performance of

the

program. In

either

case,

each

time the

work area

accessed

the

contents

are

overwritten. This is

the most important

feature

remembered, as

we have

manually

clear

the contents of

the

work area

or the

header

line

at certain

points

the program.

data:itab_obj

type

itab1, itab_obj1 like

itab2

with

header

line,

itab_obj2

like table

mara

with

header

line

‘defined

from

ABAP

Dictionary,tab_obj.

write:

itab_obj1

‘

Header line,

itab_obj1[]

‘Body

[just

writes

the last

row as

its

not

the

loop]

The

above

table creates

internal

table object

from the

type

defined

Table 1. itab_obj

an internal

table

data

object of

itab1

without

header

line.

itab_obj1

internal

table data

object of

itab2

with

header

line. As

mentioned

before, in latter case both

internal table

and

header

line

the same

name. It

differentiated

shown

above.

Processing

Internal Tables: Internal

tables

can

processed

either

as a

whole

individual

lines.

When

internal

table is

processed

on whole

you

address

the

body

the internal table whereas

when internal

table

processed

line by

line you

address

the header

work

area of

the

internal

table.

Note: If

you

are using

internal table

with

header

lines

they

are

processed

separately

because both

the same

name. The body

of the

internal table is

denoted

by <itab>[]

and

header line of

the

internal

table is

denoted

by <itab>. If

the

work

area

header

line

declared

separately, then they

can

process

with

their own

names.

First let us

discuss

the operations

that favor

the

entire

internal

table

processing.

Initializing

Internal

Tables:

There

are

three

statements

initialize the

internal

table with

its

own unique

features. CLEAR <itab>. This statement

clears

the internal

table

and

its

contents

only but

the memory

occupied

not cleared.

The

unique

feature of

this statement is it

can

used

to clear both

the

body

and header of

the internal

table

separately.

To clear

the

body of

the internal table

use <itab>[]

and

clear

the header

the internal

table

use

<itab> as

shown

Table 3. clear : itab_obj1,

‘

clearing

the header

line

the

internal

table

Itab_obj1[]

‘

clearing

the body

the

internal table

REFRESH <itab>.

This

statement

always

the

clear

the body

the

internal

table, header

the internal table cannot

be accessed. As

with

CLEAR statement, the

memory

remains allocated.

refresh

itab_obj1

‘

clearing

the

body

the

internal

table

FREE

<itab>.

This

statement always applies

the

body of

the

internal

table, header

line

cannot be

accessed. But if you

want

really

release

the

memory

allocated

the

internal table this

statement

used. But the

memory

assigned

the header line

remains

allocated.

free itab_obj1

‘

clearing the

body

the

internal

table

Assigning

Internal

tables.

Internal

table

can

be assigned

to another internal table if

they

are

compatible

and

convertible. The entire contents

one

internal

table are assigned

to the

other. When you

are

using

Internal

table

with

header

line

Only

concern

whether

you

are processing

the

body

the

work

area

the

internal table, if it’s

the

body

then

itab[] is

used if

it’s

the

header line then

itab

used.

Internal

tables

can be

assigned

using

the MOVE

statement as with the

other variables.

Alternatively

you

can

use the ‘=’ statement as

follows. MOVE <itab1> TO <itab2>

“

If the

work area

processed

MOVE <itab1>[]

TO <itab2>[]

“

the

body is

processed

MOVE <itab1[]>

TO <itab2>ldquo; This returns

ERROR MOVE

<itab1>

TO <WA>

“

Internal

table header

line

assigned

Alternatively

you

can

use, <itab1> =

<itab2>

“

When

the work

areas

accessed <itab1[]>

<itab2[]>the

body

is accessed

<itab1[]>

= <itab2>

“

Returns ERROR n

=0.

do.

= n +1. move ‘1’

wanum.

move

to wanum1.

move

itab_obj.

append

itab_obj.

while n <=10. move

‘2’

to wanum.

move

‘10’

wanum.

move wa to itab_obj.

append

itab_obj. loop

at itab_obj.

write:/ itab_objnum,

itab_objnum1.

endloop.

Output 111213141516171819110210Now

the

internal

table ‘itab_obj’ has

values as

shown

above.

Alternatively

you

can

use equal

statements

well.

3. Comparing

Internal Tables: Internal

tables can

compared

with

the operands

that are

used

compare other

data

objects. The

most important

criteria

for

comparing

the internal table

are

the

number

lines

they contain.

The

larger

the number

lines, the

larger

it is

for comparisons.

If the

both

the

internal tables

have

same number

lines, then

they

are

compared

line by

line. The

operands

used

for

comparisons are LE, LT,

GE,

GT,

EQ, NE.

Except

for

EQ, the comparison stops

at the

first pair

components

that identifies

the

condition false.

Sorting

Internal Tables: If

you want to

sort

standard

hashed

table using

its table key

(defined at

the time

declaration),

the

following

syntax applies: SORT <itab>

[ASCENDING|

DESCENDING]

[AS TEXT] [STABLE]

the absence

the

table key

field

during declaration

the

default key

the nonnumerical

field of

the table. You

cannot

sort

sorted table, as

they

are

sorted

dynamically

using

the key

specified at

the time

declaration. If

you

want

to sort a

standard

or hashed

table

using

different

key the

following

syntax applies:

SORT <itab>

ASCENDING|DESCENDING]

AS TEXT

[STABLE}

<field1> ASCENDING|DESCENDING]

AS TEXT…. The

above

syntax sorts

the

internal table according

to the

instead

the table

key. ASCENDING|DESCENDING addition:

the

name implies, this

addition

is used

to sort the

fields either

ascending or

descending

order specified. AS TEXT

addition:

This

addition

used

sort

the

strings in alphabetical

order. It

can

used

to sort

the

entire table

or a

single

field

with

the

provision

that

it must be type C. Without

this

addition,

the system

sorts

according

the hardware

platform. STABLE

addition:

you sort a

table

several times

using the

same key, the sort

order

changes

often.

order

have

a stabilized

order

this

addition

used

that

the sort order

does

not change.

sort

itab_obj ‘

sorts

the

itab (from Table 1)

using

table

key in

ascending

(default)

sort

itab_obj

num descending

‘

sorts

itab

using

key

defined

descending order

Sort itab_obj

num1 descending.

Loop

at itab_obj.

Write:/ num1, itab_objnum.

Endloop. Sort

itab_obj

num1

descending.

Loop

itab_obj.

Write:/ itab_objnum1,

itab_objnum.

Endloop.

Sort

itab_obj by

num1

descending

stable. Loop

at itab_obj.

Write:/

itab_objnum1,

itab_objnum.

Endloop. Output

The

first write Statement

outputs

have

taken

only

values) 10

The

second

write

statement

may

output

10 1 9 1 As

you see although

you

sorts

descending

order the

itab_objnum

changes

first and

second

output.

But

with

addition STABLE

you

always

have

the same

order

doesn’t matter

how

many

times

you

sort.

The

third

write

statement with STABLE

10 2 9 1

Operations

for

Index

Tables: The

following

operations

are

allowed

only

for Index

tables

(i.e.)

Standard and

Sorted

Tables. Of

all the

three

tables

listed in this

document, Standard

table

flexible.

As it

does not

allow

UNIQUE key,

there are not

many

constraints

be checked before filling

the table. Hence, it is

advisable to create a

standard

table

and

then

copy to the table of

need.

Appending

Table

lines:

Appending

the table

one

the

quickest

ways

fill the

index

tables.

The

simple form of

Append

follows: APPEND <itab>. When

an internal

declared

with

the

header line,

the

above

statement

moves the

contents

from the

table (defined in <line type>)

the header line

and

then

copied

the

body

the internal table. If

the

Internal

table and

work

area

and

declared

separately

with

the

same <line

type>

then

the

following

syntax applies.

APPEND

<wa> TO <itab>. As

mentioned

before, it is

always

better to declare

work area

and

internal

table separately in

terms

performance.

Appending

Several

Lines

of Internal

Table: APPEND

LINES

<itab1>

[FROM

<n1> TO <n2>]

TO <itab2>

The

above

statement

used

append

the

whole of

<itab1>

<itab2>. Note: Often

during programming, you

might

not realize

what

APPEND

exactly

does. At any

case,

it always

adds

the table thereby keeping

the

existing

entries

the table

not empty.

The

<n1>

and

<n2>

determines the

index

of the

first and

last

lines

<itab1>

to be

copied to

<itab2>. In

the case of

Sorted

table,

the same

applies

except we have to keep

with

the key

defined

during

the

declaration

internal

table.

The

program below shows

two

forms

of append

statement depending

the header line

declaration of

the

internal

table

data

: begin

of struct,

matnr

like maramatnr,ersda

maraersda,

ernam

maraernam,

end

of struct.

types

tab

type

standard

table

struct.

Data:

itab

table

tab

with

header

line, itab1

table

tab,

like line of

itab. select matnr

ersda

ernam from mara into

corresponding

fields

of itab. append itab. endselect. Select matnr

ersda ernam from mara into

corresponding

fields

wa. append

itab.

endselect. Alternatively

you

can

modify

the select without

append and

endselect statement as

shown.

This

statement works

the

same

way

the

above but

better in

performance.select

matnr

ersda ernam from mara appending

fields

of itab. endselect. select

matnr

ersda ernam

from

mara appending

fields

of table itab.

Inserting Table

lines: The

INSERT

statement allows

you to

insert lines

the

Index

tables. This

command

opt for Sorted

table. Though

can

use this

command

for

standard

table, APPEND

considered

be the

best

terms

of performance. Like

APPEND,

you can

insert

either a

single

line

or multiple

lines

the

table. To

insert

single

line

the

following

syntax

applies:

INSERT

<line>

INTO <itab>

[INDEX <index>]

The

<line>

can

a work

area that is

either

compatible

convertible

the

<line type> declared

with

the internal

table.

Without

the

INDEX addition,

this

statement is

allowed

only within

a loop

that

it inserts

the lines to internal

table

thereby

incrementing

index

automatically. With the

INDEX addition,

the

internal

table is

filled

before

the line specified

<index>

and

the

following line’s

index

incremented

one. When

the

total number of

lines

an internal

table

equal to <index> 1,

the

<line>

inserted

at the

end

the

local

table. If

table

has

less than

<index>

lines, SYSUBRC

set

4. Inserting

several

lines: The

following

syntax

applies

when

you

want

insert several

lines

from one

internal

table to

the

other

specifying

the <index>. INSERT

LINES

OF <itab1>

INTO <itab2>

[INDEX <index>]

The

above

statement inserts

the lines from <itab1>

to <itab2> line

line

like the above INSERT

statement. INSERT LINES

OF <itab1>

[FROM

<n1>

TO <n2>]

INTO <itab2>

[INDEX

<index>] The above statement specifies

<n1>

and

<n2>

thereby

the first

and

last lines of

<itab1>

<itab2>.

Data : begin

of struct,

Empno

type I

Empname(50)

type

char, End

of struct.

Types

tab

type

sorted

table of

struct with

unique

key

empno Data

itab like

tab

with

header

line,

Jtab

tab

with

header

line, structempno

‘0001’.

structempname

‘Stephen’.

Insert

struct into

itab. structempno

‘0002’.

structempname

‘Jack’.

Insert

struct

into

itab. structempno

‘0003’.

structempname

‘Jill’.

Insert

struct

into

itab. Loop

at itab. Write:/ itabempno,

itabempname.

Endloop.

Output

0001

Stephen

0002

Jack

0003

Jill

Insert

lines

itab

into

jtab.

Loop

at jtab.

Write:/ jtabempno,

jtabempname.

Endloop.

Output 0001

Stephen

0002 Jack 0003

Jill The

above

program shows

the

demonstration

both

the insert statements

for

a sorted

table

with

unique

key. 3.

Reading

Lines

using the

Index.

In addition

inserting,

lines

from the local

tables

can

read

using READ statement. The syntax

follows.

READ TABLE <itab>

INDEX <index>

<result>. The

system

reads the

line

with

the <index> from the

table

<itab>. Read

table itab

index

into

struct. Write:/ structempno,

structempname.

Output 0002

Jack

The above

program

reads

single

entry from internal

table (itab)

with

index

2. 4. Changing

Lines:

You

can

change a

single

line

group

of lines using

the

MODIFY

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To change

single

line

of the

local table without

the condition the

following

syntax

is used. MODIFY <itab> from <wa>

The

<wa>

must be compatible with

the

<line

type>

defined

(declared

with

the

internal

table). It

searches

for

the contents

the

internal

table whose

table

key

values

correspond

the

values

<wa>

and then

the

table

modified. To

change one

more lines that meet

certain

condition

the following

syntax

used. MODIFY <itab>

from <wa>

TRANSPORTING

<f1>…<fn> WHERE

<cond>

The <wa> must

compatible

with

the <line type>

defined

(declared

with

the

internal

table). It

searches

for

the contents

changed and

contains

the new contents

well. All the

lines

of the

internal

table that satisfies the

condition

changed. Structempno

‘0003’.

Structempname

‘Jason’ Modify itab form struct. Modify

itab from

struct transporting

empname

where

(empno

‘0003’).

‘

This

the

alternative

way

modify, but

it changes

several lines

exist. Loop at

itab. Write:/

itabempno,

itabempname.

Endloop Output

0001

Stephen 0002

Jack

0003

Jason

The

above

program demonstrates

the use

of MODIFY Statement.

‘struct’

compatible

with

the

internal

table (itab)

line

type, the

internal

table is

searched

for

the

entries

that

are

compatible

with

the work

area and

they

are

modified. Deleting

Lines

from Internal

Table: To

delete single

more lines from the

internal table using

index

use DELETE

statement. To

delete

line

using

the

index

the

syntax

follows: DELETE

ITAB

[INDEX <index>]

The

above

statement deletes

the line from

the internal

table

<itab>

that

corresponds

to the

INDEX <index> and

reduces

the

subsequent

lines

Without the

INDEX option

can be

only

used within

the loop

and

the

manipulation is

carried

implicitly

using SYTABIX.

delete more lines using

the

index

the

syntax

as follows: DELETE

ITAB [FROM

<n1>

TO <n2>]

WHERE

<cond>

The

above

statement deletes

all

the

lines

from index <n1>

<n2>

that

satisfies

the

condition. If

you

not

specify

FROM

<n1>

the system deletes

from the first

line

till <n2>. Likely

If you

not specify

<n2>

the

system

deletes all lines

from <n1>

till the end

the

table. Do

N =

+1. Itab_obj1num

Itab_obj1num1

Append itab_obj1.

While n<=5. Loop at

itab_obj1.

Write:/

itab_obj1num,

itab_obj1num1.

Endloop. Output

10 3 10

Delete

itab

index

Delete

itab

from 1

where

num <

2. B

The statement

deletes

the second

entry

from

top of

the internal

table. The

statement

B deletes

the

entries

from index

index

where

the first field

is less

than

(i.e.)

the

first entry

of the

internal table. LOOP

Operations

using INDEX.

You

can

process

an internal within

a loop

using

the

index.

The

syntax

is as

follows. LOOP

<itab>

[FROM

<n1>

<n2>]

[WHERE <cond>]

ENDLOOP

The

above

statement loops

the internal table

from index

<n1>

index

<n2>

that satisfies

the

condition

<cond> and

then

processed. The loop

statement

can be

executed

even

without

the

additions, except

that whole internal table

processed, but

it’s

advised

that

wherever

you

meet

conditions,

its

better

specify

in order

improve

the

performance. Operation

for

ANY TABLE:

The

operation

listed

applies

any table

type,

but

you know the

table

type

its

better

use

the apt command

for

that table

type. For

instance,

you

can

append lines in a

standard

table using

both

APPEND and

INSERT

command,

but

APPEND

preferred

INSERT for performance

reasons. The following

shows

the

operations for any

tables. The most important

thing

these

operations

is,

work for any

type

table; you

must use

the operations

that

are

common (i.e.)

you

must

specify

the

key

but not

the index. 4.

Inserting

Table lines:

The

INSERT

statement allows

you

insert

lines

the Index

tables.

This

command

opt for Sorted

table.

Though

can

use this

command

for

standard

table, APPEND

considered

be the

best

terms

performance.

APPEND, you

can

insert either

a single

line or

multiple

lines

to the

table. To insert

a single line to the

following syntax

http://erpgenie.com/abaptips

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by Joomla for

ERPGenie.COM!

Generated: 20

April, 2007,

01:21

ERPGenie.COM

ABAP Tips and

Tricks

Database

applies:

INSERT

<line>

INTO TABLE

<itab>

The

<line> can

work area

that

either

compatible

or convertible to

the

declared

with

the internal table. Inserting

several

lines:

The

following

syntax

applies when

you

want to

insert several

lines

from one

internal table to

the other

specifying

the

<index>. INSERT

LINES OF <itab1>

INTO

TABLE

<itab2>

The

above

statement inserts

the lines from

<itab1>

<itab2>

line

the above INSERT

statement. INSERT

LINES

OF <itab1>

[FROM

<n1> TO <n2>]

INTO TABLE

<itab2>

The

above

statement specifies

<n1>

and

<n2>

thereby

the first

and

last lines of

<itab1>

<itab2>.

As you

can

see the

INSERT

statement of Index

Table and

for

All Tables

differs

the

keyword

TABLE.

Generally,

for

All tables

you need to include

the

TABLE

keyword

most of

the statements. If

it’s

Standard

table, the

line is

appended

the

end of

the internal table, if

its

sorted

table, the line

inserted according

the

table

key

and

for

Hashed

table, the

line

inserted

according

the hash

algorithm. Data

: begin

of struct,

Empno

type I

Empname(50)

type

char, End

of struct.

Types

tab

sorted

table

struct

with

unique

key

empno

Data

: itab

tab

with

header

line, Jtab like

tab

with

header

line,

structempno

‘0001’. structempname

‘Stephen’.

Insert

struct into

table itab.

Struct

empno

= ‘0002’.

structempname

‘Jack’.

Insert

struct into

table itab. structempno

‘0003’.

Structempname

‘Jill’.

Insert

struct into

table

itab.

Loop

at itab.

Write:/

itab

empno, itabempname.

Endloop.

Output 0001

Stephen

0002

Jack

0003

Jill

Insert

lines

itab

into

table

jtab. Loop at

jtab. Write:/ jtabempno,

jtabempname.

Endloop. Output

0001

Stephen

0002

Jack

0003

Jill

The

above

program shows

the demonstration

of both

the insert

statements

for

a sorted

table with

unique key.

It is same

as example

demonstrated

for

INSERT

statement for

INDEX tables.

order

differentiate

that

only ‘TABLE’

key is

included in

INSERT

statement for

ALL

TABLES operations, I

have

given

the

same

example. Changing

Lines:

You

can

change a

single

line

group

of lines using

the

MODIFY

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To change

single

line

of the

local table without

the condition the

following

syntax

is used. MODIFY TABLE

The

<wa>

must

be compatible with the

<line

type>

defined (declared

with

the internal

table). It searches

for

the

contents

the

internal

table

whose table key

values

correspond

the values

<wa>

and

then the

table is modified. To change

one

lines

that

meet certain

condition the

following

syntax

used.

MODIFY TABLE <itab>

from <wa>

TRANSPORTING <f1>…<fn>

WHERE

<cond>

The

<wa>

must be compatible with

the

<line

type>

defined

(declared

with

the internal

table). It searches

for

the

contents

changed

and contains

the

new contents

well. All

the

lines

the internal

table

that

satisfies

the condition is

changed.

Structempno

‘0003’.

Struct

empname

‘Jason’

Modify table itab form struct.

Modify

table itab

from struct transporting

empname

where

(empno

‘0003’).

‘

This

the

alternative way

to modify, but it changes several lines

exist.

Loop

at itab.

Write:/ itabempno,

itabempname.

Endloop

Output 0001

Stephen 0002

Jack

0003

Jason

The

above

program demonstrates the

use of

MODIFY

Statement.

As ‘struct’ is

compatible

with

the

internal

table

(itab)

line type, the internal

table

searched

for

the entries that are compatible with the

work area

and

they are modified.

It is same

as example

demonstrated

for

INSERT

statement

for

INDEX tables. In

order

differentiate that only

‘TABLE’

key

included

INSERT statement

for

ALL

TABLES

operations,

have

given

the

same

example. Deleting

Lines: You

can

delete

single

line

or group

lines

using

DELETE

statement. The system searches

the table

using

linear search,

binary

and

hash

algorithm for

Standard,

Sorted

and

Hashed

tables

respectively. If

the table

contains

NONUNIQUE

key, the

first entry

changed.

To delete

a single

entry of

the internal

table

using

the

table key,

one of

the following

syntax

is used. DELETE TABLE <itab>

FROM

<wa>

The

above

statement deletes

single

entry

from the

internal table

using

the corresponding

table

key

from <wa>. The

<wa>

must

be compatible with the

line

type of

<itab>. DELETE

TABLE

<itab>

WITH

TABLE

KEY

<k1>

<fn> The above

statement is

exactly the

same

but you

have

explicitly

define

the table key

fields.

To delete a group

lines

of the

internal table that

meets

certain

condition, the

following syntax

used.

DELETE TABLE <itab>

WHERE

<cond> To

delete the

adjacent

duplicate

entries

the

following

syntax

is used.

DELETE ADJACENT DUPLICATE ENTRIES

FROM

<itab>

COMPARING <f1>…<fn>

[ALL

FIELDS].

In order

to execute this

statement

successfully,

we have to give the

following

options:

you

give

the COMPARING <f1>…<fn>,the

fields

<f1>

till <fn>

are compared

with

all

the lines of

the table, if

it founds

identical entries, they

are

deleted.If you

give ALL

FIELDS,

all the

fields of

the internal table

compared

and

upon

finding

identical

entries,

they

are

deleted.By omitting both

the options,

the

key

fields of

the internal table

are

compared

and

upon

finding

identical

entries,

they

are

deleted. Move

‘1’

wanum.

Move

‘10’

wanum1.

Append

itab_obj. Loop at

itab_obj. Write:/ itab_objnum,

itab_objnum1.

Endloop.

Output

111213141516171819110

1 10

10wanum

wanum=

delete table

itab

from wa.‘

This

statement

deletes

the content

itab

that

corresponds

delete adjacent

duplicate

entries

itab_obj

comparing

all fields

‘A

delete adjacent

duplicate

entries

from

itab_B

The statement A

deletes

the entries where all the

fields

are identical in adjacent

rows, (i.e.)

[1 10 &

10]

The

statement B

deleted

all the

entries

that

have

identical values in the

first field, (i.e.) [Internal Table

itab_obj

contains only

10]

Reading

lines: To

read

single

entry

an internal table

any

table type

use

the

following statement. READ TABLE <itab>

<key>

explained

above

in order

to be

valid

statement

for

any

type of

table,

you

must use

the <key>

not the

<index>

that

you use

for

INDEX tables.

The

key you

specify

can be

either

table

key

user defined

key. First

lets

look at

table

key. When

you

don’t

want specify

all the table keys

explicitly you

can use

the

following

statement. READ

TABLE

<itab>

FROM <wa>.

Alternatively

you

can

specify

the table keys expicitly in the

READ

statement

follows:

READ

TABLE

<itab>

WITH

TABLE

KEY

<k1>

= <fn>. If

you

want

specify

different

key other

than

table

key,

you

can use

the following

statement. READ

TABLE

<itab>

WITH

KEY <k1>

<f1>

…. <kn>

<fn>. When you

compare both

the

READ

Statements, you can easily

trace out, ‘TABLE’

keyword

is missing.

The

following

program demonstrates

the use

of all the READ

statements.Structempno

‘0001’.

Read

table itab

from struct. Write:/ structempno,

structempname.

Output

0001

Stephen read

table

itab

with

table

key

empno

‘0002’

write:/ itabempno,

itabempname.

Output

0002

Jack

read

table itab

with

key

empname

‘Jason’.

Write:/ itabempno,

itabempname

Output

0003

Jason

The first

output

reads

from the internal

table

using

the table key

from the work

area. The only

requirement

work area

must be compatible with

the

line

type

the

internal

table. The

second output reads

from the internal table

with

the

table key

defined

explicitly. The third

output

reads from the

internal

table using

a different

key

defined

explicitly

but

not

the

table key. There is

complicate

form

of READ statement where

you can

retrieve

from

the internal table

comparing

the fields

the

work

area and

internal table and

transporting the

required

fields in to

the same

work area.

Here

you can

see

that

same work

area is

used

check

the

entries

against the

internal table and

used

for

output

as well. The statement uses

the following

syntax.

READ

TABLE

<itab>

[COMPARING

<f1>…<fn> ALL

FIELDS]

FIELDS |

NO FIELDS]

you

can

see

both

the

comparing

and transporting

are

optional and

then

it behaves

normal read statement.

The

work

area must be

compatible

with

line

type

the internal

table.

Structempno

‘0003’.

Read table itab struct into

struct

comparing

empno

transporting

empname

Write:/ structempno,

struct

empname

Output 0003

Jason

The above

statement is

not

necessary

for

this table but

just for understanding

the READ

concept. The

work

area is

filled

with

‘0003’

and

the

statement

reads the

internal table by

comparing

the

corresponding

entry in the work

area and

then

the

‘empname’

field

transported to the work

area. Processing

Table

Entries

Loops.

Loop

statements

are used

process

the

entries

the Internal

Table. There are lots

options

order

process

the required

entries

the

loop.

The

syntax

is as

follows:

LOOP AT <itab>

[INTO <wa>]

[WHERE

<cond>]

ENDLOOP. As

you

can

see the

INTO <wa>

and

WHERE <cond>

are optional.

If you

use the

loop

without

any

options,

all the entries

onebyone

are

processed

from the

internal

table. The

<wa>

must

be compatible with the

line

type of

the

internal

table. Generally, the INTO <wa> is

used when

the

internal

table is declared

without

the

header

line.

But

performance wise, it

better to

declare the internal table without

the

header

line

and

declare a

separate work

area that is

compatible with

the

line

type

of the

internal table.WHERE

<cond>

option

used

avoid

processing

all the

entries

the internal

table.

Hence

the internal

table contents

that

satisfies

the condition will enter the loop

and

further they

are processed

according

the requirements. LOOP

<itab>

TRANSPORTING NO FIELDS WHERE

<cond>

the

statement indicates, none

the

internal table fields

are

transported

in to the

loop,

even

the entries

that satisfy

the

condition. But this

statement

used

at the

high

end

where you

want

to find

the

number

of lines of

internal table

that satisfies

certain

condition.

The

following

program explains

each

the

statements

above

clearly,

Data : begin

struct Roll_no type

Name(50)

type

c, Mark1 type

I,type

I, End

of struct.

Data

: itab

standard

table

struct,

line of

itab, Itab1

like sorted

table of

with

header

line, N

type I. Waroll_

no =

‘121’.

Wa –name

‘Wilson’.

–mark1

‘80’.

–mark2

‘85’

Append

itab.

Waroll_

‘122’.

Wa –name

‘William’.

mark1

‘82’.

Wa mark2

‘45’

Append

wa to itab.

Waroll_

‘123’.

Wa name

‘Thomson’.Wa mark1

‘76’.

mark2

‘54’ Append

itab. Waroll_

‘124’.

Wa name

‘Daniel’.

mark1

‘87’.

mark2

‘54’

Append

wa to itab.

Insert

lines

of itab

from

itab1.

Loop

at itab

into

wa. Write:/

waroll_

no,waname,

wamark1,

wamark2.

Endloop,

Output 121

Wilson 80

122

William

123 Thomson

54 124

Daniel

Loop

itab1.

Write:/

itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endloop.Output

121

Wilson 80 85

122

William

123 Thomson

124 Daniel

54 Loop at

itab

into

where

roll_no

= ‘124’.

Write:/ waname,

wamark1,

wamark2.

Endloop.

Output

124

Daniel 87 54

Loop

at itab1

where

roll_no

‘123’.

Write:/

itab1name,

itab1mark1,

itab1mark2.

Endloop. Output

123

Thomson

loop

at itab1

transporting

no fields

where

mark2

‘54’. N

+1 ‘ Initialize

0. endloop.

Output 2

Control Level Processing

Control

Level

Processing

internal

table means

that you can divide the

internal

table into

different

groups

based on

certain

fields.

A very

important

aspect of

the control

level processing

sorting

the

internal

table. The first field

the

internal table

has

the highest

control

level and

on.

Therefore when

you

declare the

internal

table the

control

levels

of all the fields

must

be known.

Once

you

declare the

internal

table defining

the

correct control

levels

for the

fields the

internal

table is

sorted

by the

first field, second

field

and

on.

The control

level

statement

has

structure

with

and

ENDAT

with

the control

levels. The syntax

shown.

<level>

<Statements> ENDAT. There

are 4

levels

defined with the

statement. FIRST

–

First Line of

the internal

table

LAST

–

Last Line of

the internal table. NEW <field> Beginning

group

entries

that has

the same contents

<field>

and

the left of

<field>

END OF

<field>

Ending

group

entries

that has

the

same

contents

as <field>

and

to the

left of <field>

control level statements

are

allowed

within

the

loop

make

optimum use

this

feature. The

program below

demonstrates

the use

of the

control

levels. Loop

at itab1. At

first

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat. Loop

at itab1. At last

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat. Loop

at itab1.

new mark2

Write:/ itab1roll_

no,

itab1name,

itab1mark1,

itab1mark2.

Endat.Loop at

itab1. At end

mark2

Write:/ itab1roll_

no, itab1name,

itab1mark1,

itab1mark2.

Endat.

Output 121

Wilson

80 85

124

Daniel 87

123

Thomson

124

Daniel 87

Creating Summarized

Internal

Tables:

create a summate

entries

an Internal table COLLECT

statement is

used. The

syntax

is as

follows:

COLLECT

<wa>

INTO <itab> The <wa>

must compatible

with

the

line type of

<itab>. This creates

sum of

all numerical

fields

in the

internal table if

the system finds

corresponding

entry

of table key

fields

between

<wa>

and

the

table. If

fails

find

an entry, the

statement behaves

like a

normal INSERT statement. The

only

prerequisite

create

summarized

internal

table is

that all the fields

that

are

not part of

the

table

key must be

numerical columns.

Determining

the Attributes

Internal Table:

This

sounds

bit strange

we are

defining

the

attributes

the internal table, then

why

need

statement

find

the attributes.

The

internal table we

declare is

static

definition

but

during

runtime it gets dynamically

assigned.

determine

the

attributes use

the following

statement. DESCRIBE

TABLE

<itab>

[LINES

<l>]

[OCCURS <n>]

[KIND <k>]

The

LINES return the

number

lines

the internal

table.

OCCURS

returns

the

value

of the

INTIAL

SIZE

the

internal

table

and

KIND

returns the

table type

of the

internal table ‘T’

for

standard

table, ‘S’

for

sorted table and

‘H’

for

Hashed table.

Exception of

Internal

Table:

APPEND

statement

used

create

Ranked

List for

standard

tables. In

order

create

Ranked

List,

declare the

internal

table and

use the

following statement. APPEND <wa>

<itab>

SORTED

by <f>. After this

statement, the

contents

are not

appended

the

last line of

the internal table

but

gets

sorted

and

inserted

in the

respective

order. The main

feature of

this statement

that it violates

that

internal

table are dynamic datasets

follows.

The

contents

<wa>

are inserted in to

<itab>

long

the

number

of lines of

internal table does not

exceed

<n>

(declared

INTIAL

SIZE). When

it exceeds the

line

discarded

thereby

defining

static declaration

internal table.

Tips

Tricks:

The number

internal

tables

in a

program must

kept

minimum

possibleIf

you

are creating

internal of

standard

type

and

going to

process

small amount

of data its

better

declare

internal

table directly using

DATA statement.Try to

avoid

using

internal

table

with

header

line; declare a

separate work

area compatible to

the internal table

line type.Always try

to use

the

system

fields

when you

processing the

internal

table entries within

the

loop.APPEND

statement

always

adds to the

last

line

the

internal

table whereas

MODIFY changes entry

that is

already

the

table.If you

are

using

internal

table within

loop that behaves

differently

at each

pass

make sure that you

have

cleared

the header

line

or work

area.If

you don’t know the

exact value or

don’t

know

the variable

till runtime

you can

address

those

values using

‘<variablename>&

rsquo;.Use the

appropriate

statements

for

Standard,

Sorted

and

Hashed

Tables

System

Fields

for

Internal Tables: SYSUBRC

–

This

common

all

the

statements

ABAP. This

system

field

is set to

when the

statement

executed

successfully

else

it is

set

to 4.

SYTABIX

–

This

system field

contain

the current

line

internal

table. The

internal

table must of

either

Standard

Sorted

table.

For

Hashed

table this

field

is not

set. As

this field is

set only

for

Index

tables

SYTABIX

set to

the index for the

following

operations. APPEND: APPEND

sets

SYTABIX

to the

total

number

entries

the internal

table

(I.e.)

index

the

last line of

the

internal

table.

COLLECT: COLLECT

sets

SYTABIX

to the

index

of the

existing

inserted line of

the

internal table. LOOP

AT: When the

internal

table enters

loop, SYTABIX

contains

the

index

of the

line

that enters loop

and

when

it exits

loop

SYTABIX

reset

the index

that it had

before

entering loop.

READ: SYTABIX

set to

the index of

the line

the

internal

table that

read. The operations

DESCRIBE, LOOP

and

READ TABLE sets

the

following

system fields

follows.

SYTFILL

– contains

the

number

of lines in the internal table

SYTLENG

–

contains

the length

the

lines

the internal

table SYTOCCU

–

contains

the initial

amount

memory

allocated to the

internal table. Glossary:

Data Object

Instance

Data type. It occupies a

field

memory

Data Type Describe

the

technical attributes

of a

Data

Object

Flat

Structure

containing

only

elementary data types Hashed

Table One type

an internal table

where

it is

accessed

using hash

algorithm and

hash

key. In

contrast

Standard and

Sorted

tables, searching

time

does

not

increase

with

the size of

the table. Header

Line It’s

a work

area

internal

table that acts

interface

the

table.

Index

Table:

Index

table uses

linear

and

index

access

the

table. It access

time

increases with the

size

of the

table

Internal

Tables

A Data Object (either declared

directly or

declared

from the

Data Type)

that

stores the

data

and

process

within

the program.

You

can

define

three

types

namely, Standard,

Sorted

and

Hashed

Table. Sorted

Table

An Internal

table

type

that is

sorted with its

specified key

Standard Table

An internal

table

that

unsorted

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