Behavior of ftWideMemo Fields and Params changed from 7.1.3 to 7.3.12

[Nilss]

We recently upgraded from SDAC version 7.1.3 to 7.3.12.

Fields of type ftWideMemo seem to return an empty string for Value property. Formerly, if assigning

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Param.Value := Field.Value 

would not cause Param.IsNull to be False, this is now the case. When assigning

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Field2.Value := Field.Value

Field2.IsNull will be True. But when an update or insert statement is generated the corresponding parameter will have IsNull = False. This causes different different parameter assignment for us, instead of being NULL they are filled with empty strings.

Is this an intentional change or an error?

[azyk]

Thank you for the information. We have reproduced the described behavior and are investigating it. We will inform you about the results.

[Nilss]

Is there any update on this?

[ViktorV]

Yes, you are right, we changed SDAC 7.3.12 behaviour. Now when setting the TMSParam.Value property to an empty string the TMSParam.IsNull property will be set to False, as in SQL Server an empty string does not equal NULL. To set the NULL value in the parameter, you should call the Clear method, like this:
MsQuery.ParamByName('myParam').Clear;
To solve the issue you can use the following code:

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if Field.IsNull then
  Param.Clear
else
  Param.Value := Field.Value;