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Enclose string parameters in quotation marks...

INSERT INTO myTable (MyField, field2) VALUES (":MyField", ":field2")

Sincerely
Ondrej Gratz

Stephen Craig wrote:
> Hi
> I'm "playing" with an Access DB and am having problems setting query
> Parameters to a String when the string is a empty.
> 
> eg
> for the query
>       INSERT INTO myTable (MyField, field2) VALUES (:MyField, :field2)
> 
> If I set the parameter ...
>     qry->Parameters->ParamByName("MyField")->Value = "";
> I get this error when I ExecSQL() "...Invalid Precision Value"
> 
> If I set the field without using parameters then all is Ok ie ...
>     INSERT INTO myTable (MyField, field2) VALUES ("", "some text")
> 
> Can I use Parameters when the fields may be Null strings?
> 
> Thanks
> Steve
> 
> 
> 

Hi Ondrej,
Thanks for the reply

If I use quotes as you described (either single or double (\")) as follows
    INSERT INTO myTable (MyField, field2) VALUES (':MyField', ':field2')
and I attempt to set parameters using
    qry->Parameters->ParamByName("MyField")->Value = "";
Then I get the error
    Parameter 'MyField' not found

Interestingly, if I revert back to

    INSERT INTO myTable (MyField, field2) VALUES (:MyField, :field2)
and set the parameter to some string and then set it to a NULL then it all
is ok.  ie...
    qry->Parameters->ParamByName("MyField")->Value = "dummy";
    qry->Parameters->ParamByName("MyField")->Value = "";
This works perfectly

I can only imagine that the first assignment is setting some parameter
property.  Initially I thought that this would be the DataType property.
But setting this to ftString prior to the NULL assignment ie...
      qry->Parameters->ParamByName("MyField")->DataType = ftString;

      qry->Parameters->ParamByName("MyField")->Value = "";
makes no difference. I get the same old exception ...
     [Microsoft][ODBC Microsoft Access Driver]Invalid precision value.

I also tried setting the parameter Attributes to paNullable
      qry->Parameters->ParamByName("MyField")->Attributes << paNullable;
Still get exception

I think I'll just have to use the dummy assignment, unless anyone can come
up with a better answer

Steve

"Ondrej Gratz" <gratzo@atlas.cz> wrote in message
news:4294958b@newsgroups.borland.com...
> Enclose string parameters in quotation marks...
>
> INSERT INTO myTable (MyField, field2) VALUES (":MyField", ":field2")
>
> Sincerely
> Ondrej Gratz
>

Hi Stephen,
I'm sorry, I didn't try it. Now I remember...some time ago "Parameter 
'MyField' not found" exception has been the reason why I use 
StringReplace function :-) instead of parameters.
I recommended quotes because I thought the SQL commmand would be wrong 
when you used NULL values ...INSERT INTO myTable (MyField, field2) 
VALUES (, )
I hope someone will give us better answer too.

Sincerely
Ondrej Gratz


Stephen Craig wrote:
> Hi Ondrej,
> Thanks for the reply
> 
> If I use quotes as you described (either single or double (\")) as follows
>     INSERT INTO myTable (MyField, field2) VALUES (':MyField', ':field2')
> and I attempt to set parameters using
>     qry->Parameters->ParamByName("MyField")->Value = "";
> Then I get the error
>     Parameter 'MyField' not found
> 
> Interestingly, if I revert back to
> 
>     INSERT INTO myTable (MyField, field2) VALUES (:MyField, :field2)
> and set the parameter to some string and then set it to a NULL then it all
> is ok.  ie...
>     qry->Parameters->ParamByName("MyField")->Value = "dummy";
>     qry->Parameters->ParamByName("MyField")->Value = "";
> This works perfectly
> 
> I can only imagine that the first assignment is setting some parameter
> property.  Initially I thought that this would be the DataType property.
> But setting this to ftString prior to the NULL assignment ie...
>       qry->Parameters->ParamByName("MyField")->DataType = ftString;
> 
>       qry->Parameters->ParamByName("MyField")->Value = "";
> makes no difference. I get the same old exception ...
>      [Microsoft][ODBC Microsoft Access Driver]Invalid precision value.
> 
> I also tried setting the parameter Attributes to paNullable
>       qry->Parameters->ParamByName("MyField")->Attributes << paNullable;
> Still get exception
> 
> I think I'll just have to use the dummy assignment, unless anyone can come
> up with a better answer
> 
> Steve
> 
> "Ondrej Gratz" <gratzo@atlas.cz> wrote in message
> news:4294958b@newsgroups.borland.com...
> 
>>Enclose string parameters in quotation marks...
>>
>>INSERT INTO myTable (MyField, field2) VALUES (":MyField", ":field2")
>>
>>Sincerely
>>Ondrej Gratz
>>
> 
> 
> 

>     [Microsoft][ODBC Microsoft Access Driver]Invalid precision value.

Switch to Jet OLEDB provider - it is native for Access and is better than 
OLEDB provider for ODBC that you use now. Connection string is:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\mydb.mdb;

//------------------------------------------
Regards,
Vassiliev V. V.
http://www.managed-vcl.com - using .Net objects in Delphi for Win32 + 
ADO.Net
http://www.oledbdirect.com - The fastest way to access MS SQL Server,
MS Jet (Access) and Interbase (through OLEDB)


"Stephen Craig" <stevecraig@ozemail.com.au> �������/�������� � �������� 
���������: news:42966bb3$1@newsgroups.borland.com...
> Hi Ondrej,
> Thanks for the reply
>
> If I use quotes as you described (either single or double (\")) as follows
>    INSERT INTO myTable (MyField, field2) VALUES (':MyField', ':field2')
> and I attempt to set parameters using
>    qry->Parameters->ParamByName("MyField")->Value = "";
> Then I get the error
>    Parameter 'MyField' not found
>
> Interestingly, if I revert back to
>
>    INSERT INTO myTable (MyField, field2) VALUES (:MyField, :field2)
> and set the parameter to some string and then set it to a NULL then it all
> is ok.  ie...
>    qry->Parameters->ParamByName("MyField")->Value = "dummy";
>    qry->Parameters->ParamByName("MyField")->Value = "";
> This works perfectly
>
> I can only imagine that the first assignment is setting some parameter
> property.  Initially I thought that this would be the DataType property.
> But setting this to ftString prior to the NULL assignment ie...
>      qry->Parameters->ParamByName("MyField")->DataType = ftString;
>
>      qry->Parameters->ParamByName("MyField")->Value = "";
> makes no difference. I get the same old exception ...
>     [Microsoft][ODBC Microsoft Access Driver]Invalid precision value.
>
> I also tried setting the parameter Attributes to paNullable
>      qry->Parameters->ParamByName("MyField")->Attributes << paNullable;
> Still get exception
>
> I think I'll just have to use the dummy assignment, unless anyone can come
> up with a better answer
>
> Steve
>
> "Ondrej Gratz" <gratzo@atlas.cz> wrote in message
> news:4294958b@newsgroups.borland.com...
>> Enclose string parameters in quotation marks...
>>
>> INSERT INTO myTable (MyField, field2) VALUES (":MyField", ":field2")
>>
>> Sincerely
>> Ondrej Gratz
>>
>
> 

Thanks, That fixed it!!!!

"Viatcheslav V. Vassiliev" <support@oledbdirect.com> wrote in message
news:4296ed4a@newsgroups.borland.com...
> >     [Microsoft][ODBC Microsoft Access Driver]Invalid precision value.
>
> Switch to Jet OLEDB provider - it is native for Access and is better than
> OLEDB provider for ODBC that you use now. Connection string is:
>
> Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\mydb.mdb;
>
> //------------------------------------------
> Regards,
> Vassiliev V. V.
> http://www.managed-vcl.com - using .Net objects in Delphi for Win32 +
> ADO.Net
> http://www.oledbdirect.com - The fastest way to access MS SQL Server,
> MS Jet (Access) and Interbase (through OLEDB)