How to Read data base table at runtime

[Former Member]

Hi,

i have an internal table with two fields they are

tablename and field name.

itab has some entries.

like :

itab-table name itab-fieldname

kna1 kunnr

mara matnr

vbuk vbeln

tvak auart

i want to read these tables with field names.

like :

loop at itab

select singe * from <itab-tablename> into <jtab>

where <itab-fieldname > = <dyanmic value from prog>.

endloop.

Is it possible to read the db table in the above scenario.

Please try to give me the solution.

Thanks,

srik

[RichHeilman]

Yes, it is. Need an example?

Regards,

Rich Heilman

[Former Member]

HI Rich,

I need an example..

Thanks in advance.

srik

[RichHeilman]

Hi, try this example program.

report zrich_0002 .

data: begin of itab occurs 0,
      tabname(20) type c,
      fldname(20) type c,
      end of itab.

data: ref_descr type ref to cl_abap_structdescr.
data: where_clause(100) type c occurs 0 with header line.

data: it_details type abap_compdescr_tab,
      wa_details type abap_compdescr.

data: new_table type ref to data,
      new_line  type ref to data,
      it_fldcat type lvc_t_fcat,
      wa_it_fldcat type lvc_s_fcat.

field-symbols: <dyn_table> type standard table,
               <dyn_wa>,
               <dyn_field>.

start-of-selection.

  itab-tabname = 'T000'.
  itab-fldname = 'MANDT'.
  append itab.

  itab-tabname = 'T001'.
  itab-fldname = 'BUKRS'.
  append itab.


  loop at itab.


* Get the structure of the table.
    refresh it_fldcat.
    refresh where_clause.

    ref_descr ?= cl_abap_typedescr=>describe_by_name( itab-tabname ).
    it_details[] = ref_descr->components[].

    loop at it_details into wa_details.
      clear wa_it_fldcat.
      wa_it_fldcat-fieldname = wa_details-name .
      wa_it_fldcat-datatype = wa_details-type_kind.
      wa_it_fldcat-inttype = wa_details-type_kind.
      wa_it_fldcat-intlen = wa_details-length.
      wa_it_fldcat-decimals = wa_details-decimals.
      append wa_it_fldcat to it_fldcat .
    endloop.

    if <dyn_table> is assigned.
      refresh <dyn_table>.
      unassign <dyn_table>.
    endif.

* Create dynamic internal table and assign to FS
    call method cl_alv_table_create=>create_dynamic_table
                 exporting
                    it_fieldcatalog = it_fldcat
                 importing
                    ep_table        = new_table.
    assign new_table->* to <dyn_table>.



    concatenate itab-fldname '<> ''' '''' into where_clause
                    separated by space.
    append where_clause.

    select * from (itab-tabname) into table <dyn_table>
                  where (where_clause).



  endloop.

Regards,

Rich Heilman

[Former Member]

Thans Rich

Thanks,

srikanth

[Former Member]

hi,

it is possible. u just define a variable

<b>DATA : VAR1 LIKE DD02L-TABNAME.</b>

now in select query u can write

select singe * from <b>(VAR1)</b> into <jtab>

where <itab-fieldname > = <dyanmic value from prog>.

endloop.

same way u can do for field name also.

[Former Member]

pawan,

i tried with ur logic. But iam getting short dump at

var2.

check the following statments.

var2 like dd03l-fieldname.

loop at itab.

var1 = itab-tablename.

var2 = itab-fieldnaem.

select * from (var1) into table <jtab> for all entries

in <ktab> where (var2) = ktab-field.

append jtab.

endselect.

endloop.

Thanks,

srik

[Former Member]

Hi

Can you make it a bit clear.

if you have itab1 and itab2.

then you can loop itab1 and

read itab2 with key = itab-field.

youcan also do select single * .

but performance wise reading is better inside the loop.endloop