🚀 go-pugleaf

On Wed, 1 Aug 2001 10:29:59 -0700, "John Biddle" <johnb@vigilant-systems.com>
wrote:

>I have a TADOQuery hooked up to a MS SQL Server 7.0 database.
>I am trying to execute a parameterized insert statement to update a
>VARCHAR(64) field that is nullable in the SQL database.
>
>ADO will not allow me to set this parameter to NULL.
>It always raises an exception:
>'Parameter object is improperly defined.
>Inconsistent or incomplete information was provided'
>
>I have tried all of the following without success:
>
>Assigning the TParameter to an empty variant (VT_EMPTY).
>Assigning the TParameter to an null variant (VT_NULL).
>Setting the TParameter Attributes to pa_Nullable.
>Setting the TADOQuery ParamCheck to false.
>
>The query works fine if I replace the parameter in the SQL text with the
>NULL keyword.
>
>I have lots of parameters in this query and would really like to avoid
>having
>to generate the SQL at runtime.
>
>Any ideas?!?!?!?!?
>

Hi John,

    I've tried to create a table like the following on MSSQL SERVER 7:

CREATE TABLE [dbo].[NULLTEST] (
  [ID] [int] IDENTITY (1, 1) NOT NULL,
  [NULLTEST] [varchar] (64) NULL 
);

Next, I've created a project that has a TADOCommand which has the CommandText

property that's filled with the following string:  

insert into NULLTEST ( NULLTEST ) values ( :NULLTEST )

Running the following lines of code, it insert a NULL in the column NULLTEST.

    ADOCommand1->Parameters->ParamByName( "NULLTEST" )->Value = Variant();
    ADOCommand1->Execute();

Sorry, but I haven't any idea to solve your problem because I can't be able to
reproduce it.

Ciao!

Giuliano