Looping through a TOracleDataSet's Cursor result

[Dan Comeau]

I'd like to loop through a TOracleDataSet's Cursor. I want to do some calculations before the data is used in a DBGrid. So, in the OracleDataSetAfterQuery I'm trying to do something like

OracleDataSet.Last;
while not OracleDataSet.Bof do
begin
OracleDataSet.Prior;
CalcSomething;
end;

The error I get is "Cannot perform this operation on a closed dataset." I'd be happy if I could loop forwards instead. I understand that the cursor may be unidirectional so that .Last doesn't work. However, .First doesn't work either. Same error message.

BTW, I'm not returning a rowid with the cursor. Would this help here? I'll go try that... I'll also try AfterFetchRecord to see if that can be used...

Dan

 

[Marco Kalter]

You will have to use the AfterOpen event instead. During AfterQuery the dataset is still closed.

You can use TOracleDataSet.DisableControls/EnableControls to prevent any visual side-effects of your calculations.

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Marco Kalter
Allround Automations

 

[Dan Comeau]

Perfect. Thanks! And thanks for the tip on DisableControls -- I had forgotten about it.