ABAP_to_the_Future

Internal Tables 2.6
This saves you a few lines of code and is wonderful for when the line structures
of the two tables are flat. However, it still doesn’t solve the problem for deep
structures. As you’ve seen, MOVE-CORRESPONDING on its own will dump the contents
of an internal table component, such as LT_RESULT, into the identically
named component in the ta rget structure. If the LT_RESULT in the target has differently
named columns, then all sorts of bizarre results might ensue. To counteract
this, SAP has come up with two new additions to MOVE-CORRESPONDING in
release 7.4. The next subsections look at them first one at a time and then combine
them.
MOVE-CORRESPONDING EXPANDING NESTED TABLES
In MOVE-CORRESPONDING EXPANDING NESTED TABLES , anything that might happen
to be in the target internal table alread y is deleted. Columns with simple values,
like numbers, are copied to their iden tically named friends. However, when it
comes to complex columns such as LT_RESULT, only fields that have the same
column name inside the nested tables would get copied. For example, the
MONSTER_NAME would get copied, because there is an equivalently named column
in the target, but MONSTER_IBAN_CODE would not, because there is no column with
the same name, only the LOCKBOX.
MOVE-CORRESPONDING KEEPING TARGET LINES
What happens in MOVE-CORRESPONDING KEEPING TARGET LINES is quite strange; if
there is anything already in the target internal table, then it stays there. Then, at
the end of the target table, extra rows are added—which is what would happen if
you just performed a MOVE-CORRESPONDING between the two tables. This is rather
like APPEND LINES OF itab1 TO itab2 , except that the two tables have different
structures, and only identically named components come across.
MOVE-CORRESPONDING EXPANDING NESTED TABLES
KEEPING TARGET LINES
As might be imagined, MOVE-CORRESPONDING EXPANDING NESTED TABLES KEEPING
TARGET LINES does both of the previous tasks at once; it acts like APPEND LINES OF
itab1 TO itab2 , copying only identically named components to the new rows,
but is also a bit clever with any intern al table components and only copies identically
named components within these structures.
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