[SOLVED] Firebird 'Integer' field with NULL value
lazarus / 16-Databases

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iru · 2015-03-08 22:43

Gentlefolk,

I have a FireBird database table with 'integer' type field with a
'NULL' value.

When I load the table into a SQLQuery-DBGrid combination the
field/cell is displayed as an 'empty' cell.
This is what I want as the user simply types data into an 'empty' cell
in the DBGrid.

If I wish to delete data in the table field, that is reset the field
in the database so that the DBGrid cell displays an 'empty' cell. how
do I do it?
How do I write a 'NULL'  into the table field?

The following code results in a 0 (zero) in the table field.

var
  vVariant : Variant;

begin
  InQ.Edit;
  vVariant := NULL;
  try
    Variants.NullStrictConvert := False;
     InQ.FieldByName('MemReg').AsInteger := vVariant;
  finally
    Variants.NullStrictConvert := True;
  end;
end;

An help appreciated, Ian

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balazsszekely · 2015-03-08 23:08

Hi Iru,

Try this:
InQ.FieldValues['MemReg'] := null;

regards,
GetMem

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iru · 2015-03-09 00:48

Thank you GetMem, fixed things nicely.

Ian