Very Computer

Help!
  I'm trying to read a memo field from Access using OLE DB.  It sys the
type of the field is an IUnknown (DBTYPE_IUNKNOWN) - but I can't do a
QueryInterface on it (it just fails with a "privileged instrution"
execption) - does anybody know what to do with this type??

Thanks
     KEEF

You want to read the field through using ISequentialStream. There is a
Microsoft example called AOTBLOB.exe that illustrates this on Microsoft
support website.

Bob Beauchemin

Quote:> Help!
>   I'm trying to read a memo field from Access using OLE DB.  It sys the
> type of the field is an IUnknown (DBTYPE_IUNKNOWN) - but I can't do a
> QueryInterface on it (it just fails with a "privileged instrution"
> execption) - does anybody know what to do with this type??

> Thanks
>      KEEF

Thanks for the help. ISequential stream works
great for reading one memo field.

However, my access table now has 2 memo fields. I
generate a select statement, and obtain a
CRecordset object. Calling "MoveNext()" on this
object causes "E_NOINTERFACE" error when
connected to the database via ODBC.

I've tried forcing the memo fields to be at the
end of the column list in the select statement,
but this does not help.

Please HELP!!

Thanks in advance

ISequentialStream. There is a

Quote:> Microsoft example called AOTBLOB.exe that

illustrates this on Microsoft

MSGV22...

Quote:> > Help!
> > I'm trying to read a memo field from Access

using OLE DB. It sys the

Quote:> > type of the field is an IUnknown

(DBTYPE_IUNKNOWN) - but I can't do a

Quote:> > QueryInterface on it (it just fails with

a "privileged instrution"

Quote:> > execption) - does anybody know what to do
with this type??

> > Thanks
> > KEEF

Sent via Deja.com http://www.deja.com/
Before you buy.

Thanks for the help. ISequential stream works
great for reading one memo field.

However, my access table now has 2 memo fields. I
generate a select statement, and obtain a
CRecordset object. Calling "MoveNext()" on this
object causes "E_NOINTERFACE" error when
connected to the database via ODBC.

I've tried forcing the memo fields to be at the
end of the column list in the select statement,
but this does not help.

Please HELP!!

Thanks in advance

ISequentialStream. There is a

Quote:> Microsoft example called AOTBLOB.exe that

illustrates this on Microsoft

MSGV22...

Quote:> > Help!
> > I'm trying to read a memo field from Access

using OLE DB. It sys the

Quote:> > type of the field is an IUnknown

(DBTYPE_IUNKNOWN) - but I can't do a

Quote:> > QueryInterface on it (it just fails with

a "privileged instrution"

Quote:> > execption) - does anybody know what to do
with this type??

> > Thanks
> > KEEF

Sent via Deja.com http://www.deja.com/
Before you buy.

This only works for a single storage object at a time. The behavior is
specified (read-only) by the provider property
DBPROP_MULTIPLESTORAGEOBJECTS. For ODBC and Jet 4 provider, this property is
set to false, meaning only one storage object can be open at a time.

You'll have to use multiple accessors, each with a single storage object and
read through each accessor individually, releasing the ISequentialStream
pointer from the first object before reading the second.

Bob Beauchemin