Generic itab in JOIN in SELECT?-CodePudding

I have a generic table in global area and i want to use it in SELECT from. Is this possible or is there a way do this ?

Example Code:

FIELD-SYMBOLS: <gt_data> TYPE STANDARD TABLE.
CLASS-DATA:  mo_data         TYPE REF TO data.  

CREATE DATA mo_data LIKE lt_data.     
ASSIGN mo_data->* TO <gt_data>.     
<gt_data> = lt_data.

SELECT data~matnr,
       mbew~malzeme_deger
  FROM zmm_ddl_mbew AS mbew
  INNER JOIN @<gt_data> AS data ON data~matnr EQ mbew~matnr
  INTO TABLE @DATA(lt_mbew).

CodePudding user response：

If the Generic table you are asking about is an internal Table which the code snippet suggests, then
No i dont think you cant build a join to work on 2 different sources.

Unless there are some new kernel developments, the select statements are converted to DB SQL statements. ABAP 7.5 documentation of Select statement refers to the from "data_source" as dbtab,View or cds_entity as possible sources.

Even if it was possible there are still other generic options that may make more sense. If the source internal data is small enough, then you can build a generic where clause to solve the problem.

Select from DBTAB  where (string_cond).

If the size of the internal table is so large that you end up with half the data in memory and half on a DB, there may be a better generic solution anyway.

CodePudding user response：

No, it is not possible. From the SELECT datasource help:

If the FROM clause is specified statically, the internal table cannot be a generically typed formal parameter or a generically typed field symbol. Objects like this can only be specified in a dynamic FROM clause and must represent a matching internal table at runtime

The above rule remains valid whether itab joined with dbtab or not.