EXEC SQL insert null date

Question

Hello,
Could anyone please tell me how I can insert a null date into an oracle table dynamically?  Here are my codes:
DATA: LV_KEY(10),
            LV_DATE TYPE D.
TRY.
  EXEC SQL.
    INSERT INTO Z_ORACLE_TABLE
    ( KEY_FIELD, OPTION_DATE )
    VALUES
    ( :LV_KEY, TO_DATE( :LV_DATE, 'YYYYMMDD' ) )
  ENDEXEC.
ENDTRY.
Somehow, Oracle gives an error if LV_DATE is initial ('00000000'), saying the date is not between -49xx to ....
I could have done the following but it is kind of dumb:
TRY.
  IF :LV_DATE IS INITIAL.
    EXEC SQL.
      INSERT INTO Z_ORACLE_TABLE
      ( KEY_FIELD, OPTION_DATE )
      VALUES
      ( :LV_KEY, NULL )
    ENDEXEC.
  ELSE.
    EXEC SQL.
      INSERT INTO Z_ORACLE_TABLE
      ( KEY_FIELD, OPTION_DATE )
      VALUES
      ( :LV_KEY, TO_DATE( :LV_DATE, 'YYYYMMDD' ) )
    ENDEXEC.
ENDTRY.
Thanks in advance for any suggestions.

Answer 1

Hi Sau Tong Calvin,
don't you mess up INITIAL ans NULL values.
In ABAP, every data type has an initial value. As opposed to other programming languages, all variables are set to their initial value before use, numeric fields get 0, TYPE N which is numeric character will take 0 in all places, strings are empty and character fields are space. ABAP date fields are type N technically, so will be '00000000'.
You can store as this using open SQL.
NULL value means there is nothing stored for this field - this may save disk space if only few records have values stored for the field. But it will make problems in a WHERE clause of selection because SPACE matches initial values but not NULL values and opposite.
I don't know too much about native EXEC SQL because I never needed in the last decade. Hopefully you can solve the task using ABAP open SQL.
Regards,
Clemens