LargeInt Fields

adoniram · Post by **adoniram** » Mon 21 Feb 2011 17:52

After update unidac to 3.60.0.15 version we cannot access LargeInt field with Value property. Instead we have to do AsInteger to work.

If we use Table.FieldByName('LargeIntField').Value it raises "Cannot access field 'LargeIntField' as type Variant" error.

On prior version (3.0.0.9) it's not happened.

AlexP · Post by **AlexP** » Tue 22 Feb 2011 08:27

Hello,

Please specify the name of your database.

adoniram · Post by **adoniram** » Thu 24 Feb 2011 16:50

SQL Server.

AndreyZ · Post by **AndreyZ** » Fri 25 Feb 2011 08:19

This error raises by the TLargeintField class and it depends only on the Delphi version you are using. Starting with Delphi 2005 you won't get such error.

adoniram · Post by **adoniram** » Fri 25 Feb 2011 17:40

But before unidac update it works.
Why?

AndreyZ · Post by **AndreyZ** » Mon 28 Feb 2011 13:16

If you don't use persistent fields, you should use the following code:

Code: Select all

TLargeintField(Table.FieldByName('LargeIntField')).Value

In this way you determine that Delphi must use the TLargeintField.Value property that is defined in the following way:

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property Value: Largeint read GetAsLargeint write SetAsLargeint;

In this case there will be no error. If you don't do this, Delphi will invoke the TField.SetAsVariant method, and this method will invoke the TLargeintField.SetVarValue method that is defined in the following way:

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procedure TLargeintField.SetVarValue(const Value: Variant);
begin
  raise AccessError('Variant'); // here this error is raised
end;

If you use persistent fields, you should use the following code:

Code: Select all

TableLargeIntField.Value

In this case the TLargeintField.SetAsLargeint will be invoked and there will be no error.

adoniram · Post by **adoniram** » Tue 01 Mar 2011 18:07

Ok,
Thanks!.

AndreyZ · Post by **AndreyZ** » Wed 02 Mar 2011 07:59

Feel free to contact us if you have any further questions about UniDAC.