SQL Mobile: BLOB col = NULL

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vvf - 20 Jan 2007 14:28 GMT

Hi All,

Thanks for your previous help on this group.

I have a new problem: I do a "select col1, col2, col3 from T1 inner join T2
on ... " where col3 is a BLOB column;

If I use cmd.GetValue(1) I get a pointer to data of col1, GetValue(2) gives
me the pointer to col2, but GetValue(3) gives me a NULL pointer (that is a
NTEXT, i.e., BLOB column.) Any idea why? I should get a ISequentialStream**
back...

Thanks!
vvf

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Marius Prisecaru - 20 Jan 2007 17:01 GMT

Hi,

My experience w/ SQL Mobile is that you have to have a column before your
BLOB column in your result set.

For example, try this:

"SELECT ID, BlobCol, Col1, Col2 FROM Table1 INNER JOIN Table2 ON ... "

where you would have a table as:

ID, BlobCol ...

Note that you include the "ID" field in your query even though you may not
need it. Then, use static_cast<ISequentialStream**>(cmd.GetValue(2)) and
dereference that to obtain a pointer to ISequentialStream.

See if that works. In fact, check your HRESULT from MoveFirst/MoveNext. It
should return 0x00040EDA (errors occurred) since you are able to retrieve
the other columns.

Marius

> Hi All,
>
[quoted text clipped - 13 lines]
> Thanks!
> vvf

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vvf - 20 Jan 2007 23:43 GMT

That worked!

Thanks!
vvf

> Hi,
>
[quoted text clipped - 36 lines]
> > Thanks!
> > vvf

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