CODEWITHSUNDEEP
delphidelphi-2010
srayner
srayner

Reputation: 1839

Using TIBDataset how do I set a DateTime field to null

TField.Clear does not work on a DateTime field, like it does for say an integer field. So how do I set the field to null?

I'm using Delphi 2010.

Currently I do this;

IBDataset1.FieldByName('EUL_START_DATE').Clear;

However the field does not get set to null, it still contains a date value.

I think this explains it, but i don't want to go messing with core delphi files. http://qc.embarcadero.com/wc/qcmain.aspx?d=78920

What if i need to reinstall Rad Studio. I would have to remember all these little patches.

Upvotes: 0

Views: 2288

Answers (1)

srayner
srayner

Reputation: 1839

In the unit IBCustomDataset from line 3480 comment out the following lines;

//if TIBStringField(Field).EmptyAsNull then
//  rdFields[FMappedFieldPosition[Field.FieldNo - 1]].fdIsNull := True
//else
//begin
//  rdFields[FMappedFieldPosition[Field.FieldNo - 1]].fdDataLength := 0;
//  rdFields[FMappedFieldPosition[Field.FieldNo - 1]].fdIsNull := False;
//end

and add in the following lines;

//NewCode IbCustomDataSet.pas Line 3480
begin
  if (Field is TIBStringField) and
    (not TIBStringField(Field).EmptyAsNull) then
  begin
    rdFields[FMappedFieldPosition[Field.FieldNo -  1]].fdDataLength := 0;
    rdFields[FMappedFieldPosition[Field.FieldNo - 1]].fdIsNull := False;
  end
  else
    rdFields[FMappedFieldPosition[Field.FieldNo - 1]].fdIsNull := True;
end
//End New Code

solution found here; http://qc.embarcadero.com/wc/qcmain.aspx?d=78920

Tested, seem to work ok.

Just remember to make a note if you need to reinstall rad studio, this patch will need to be re-applied.

Upvotes: 1

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