topic Re: Logical Tables in Application Development and Automation Discussions

Logical Tables

Former Member — Fri, 18 Apr 2008 21:02:28 GMT

Hi Everyone,

what are logical tables in ABAP?

thanks

Re: Logical Tables

Former Member — Sat, 19 Apr 2008 01:21:45 GMT

Hi,

Views are generally called "Virtual Tables"

Views are generally used to get data from more than one table .

The main advantage is Security.

Reference Link:[http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ea31446011d189700000e8322d00/frameset.htm]

Apart from Virtual Tables we have logical database tables too.

Logical database tables are programs which retrieve data from databases and makes it available to the application programs which use the LD.

LD links the database and the application programs,

Reference link : [http://help.sap.com/saphelp_46c/helpdata/EN/9f/db9b5e35c111d1829f0000e829fbfe/content.htm]

Reward Points of helpful.

Thanks and Rewards.

Re: Logical Tables

former_member254848 — Sat, 19 Apr 2008 02:32:17 GMT

Hi,

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

*Reading a SAP standard logical database (DB M - MRP Documents) in your ABAP/4 program. *

start-of-selection.

get is equal to select * from....

get mdkp.

check field-name.

get mdtb.

check field-name

end-of-selection.

If you need to find the logical database for a table name, you can used SE36 - Logical Database Bulider.

Steps :-

Go to transaction SE36

Click Extras -> Table usage

Supply the Table name and hit enter.

A Display Logical Database will be shown on a pop-up windows.

Below klink will give you more information about the LDB

http://help.sap.com/saphelp_46c/helpdata/EN/9f/db9b5e35c111d1829f0000e829fbfe/content.htm

Re: Logical Tables

Former Member — Sun, 20 Apr 2008 05:34:13 GMT

Hai

Swapnali,

Logical tables means logical databases, which we use frequently in executable programs due to its most common use to read data from database tables and linking them to executable ABAP programs while setting the program contents.

1. Logical databases provide a particular view of database tables.

2. It is appropriate to use logical databases if the database tables you want to read correspond largely to the structure of the logical database.

3. The data structure in a logical database is hierarchical. Many tables in the R/3 System are linked to each other using foreign key relationships

4. Logical database can read the lines of these tables one after the other into an executable program in a sequence which is normally defined by the hierarchical(tree) structure.

Major Tasks of Logical Databases:

1. Reading the same data for several programs.

2. Defining the same user interface for several programs.

3. Central authorization checks

4. Improving Performance (Response time)

-> it has also been possible to call logical databases independently of this tool using the function module LDB_PROCESS.

-> This allows you to call several logical databases from any ABAP program, nested in any way.

-> You edit logical databases using the Logical Database Builder in the ABAP Workbench.

If useful , reward points.

Thank you,

G.V.K.Prasad

Edited by: PRASAD GVK on Apr 20, 2008 7:34 AM

Re: Logical Tables

Former Member — Mon, 21 Apr 2008 05:44:01 GMT

The Logical Database is special type of ABAP program that combines the contents of certain related database tables and retrieve some related data and make it available to application programs.Mostly used for HR programming.

In other words, a LDB is a method by which ABAP programs read and process the data. The sequence in which the data is supplied to the program is determined by a tree structure.

The LDB usually consists of the following components.

Structure

Selections

Database programs

Logical databases have a tree structure.

A logical database can contain a maximum of 300 tables

Functions of LDB:

Data retrieval :

The personnel data of each employee is loaded into the main memory where it can be accessed for processing.

Screening :

Employees can be selected according to the organizational criteria entered on the selection screen.

There are two types of screening..Person selection and data selection period.

Person selection defines those employees for whom a report is to be run.

Authorization check : This ensures that the person starting the evaluation Is authorized to access the report data.

Regards,

Mrunal

Intelligroup Inc.