Using CAST(), I want to assign null value to type of Date field.

Hi.

I could assign *normal date value* or *null value* into type of Date
field using TO_DATE() under Oracle7.3.

But, In case of Interbase4.2, I couldn't assign both values at one codes
like using Oracle7.3.

How can I cast string to date type using CAST() ?

I want to assign null value to type of Date field.

You also know that "ParamByName('BIRTH').Clear" has no effect,
just happen a error called "Data type unknown".  Clear method cann't be
used !!!

  with InsertQuery do begin
    Close;
    SQL.Clear;
    SQL.Add('INSERT INTO BBB ( CODE, NAME, BIRTH, ADDR, AMOUNT ) ');
/////////////////    This code is for Interbase4.2   -------  Error !!!!

   SQL.Add('VALUES ( :CODE, :NAME, CAST(:BIRTH AS DATE), :ADDR, :AMOUNT
)' );
/////////////////    This code is for Oracle 7.3     -------- Ok !!!!
    SQL.Add('VALUES ( :CODE, :NAME, TO_DATE(:BIRTH), :ADDR, :AMOUNT )'
);
/////////////////
    ParamByName('CODE').AsInteger := niCode;
    ParamByName('NAME').AsString  := 'Shawna';
    ParamByName('ADDR').AsString  := 'NewYork';
    ParamByName('BIRTH').AsString := '2002-12-25';  //  or '' ( null
vlaue)
    ParamByName('AMOUNT').AsInteger := 1000;
    ExecSQL;
  end;

Good Luck.

-shawna