BUG: pcbValue Shows 1022 Even if Size of Available Data > 1022

ID: Q141810

The information in this article applies to:

Microsoft Open Database Connectivity, version 2.0

BUG#: 2400 (QJET)

SYMPTOMS

When fetching an OLE object from a Microsoft Access 2.0 database (*.MDB) using the 16-bit ODBC Access driver, SQLFetch always returns a pcbValue of 1022 bytes even though the actual size of the data is greater than 1022.

WORKAROUND

Microsoft recommends moving to the 32-bit ODBC Access driver, because this behavior is not seen in the 32-bit version.

MORE INFORMATION

To reproduce this problem:

Create a table (mytable) in Access 2.0 with two fields: Col1 text, Col2 OLE Object.
Insert some text data into col1.
Open Paintbrush. Scribble, cut and paste the picture into Col2 (actual size > 1022 bytes).

Create a 16-bit datasource to this Access database.

Then, from ODBC Test:

Full connect to the Access database.


SQLExecdirect ( Select * from mytable)

SQLBindCol(icol=2, fCType=SQL_C_CHAR=1, cbValueMax=1023)

SQLFetch:
   Return:   SQL_SUCCESS_WITH_INFO=1
                icol, fCType, cbValueMax, pcbValue, rgbValue
                2, SQL_C_CHAR=1, 1023, 1022, "151C2E00020...."

NOTE: Even though the number of bytes of available data to return for the column is 40K, the pcbValue shows 1022. pcbValue returns the correct number of bytes if the cbValueMax is set to 1022 or less. This behavior is not seen in the 32-bit ODBC Access driver version 3.x.

STATUS

Microsoft has confirmed this to be a problem in 16-bit Access ODBC driver version 2.00.2317. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: 2.00.2317 Access ODBC Driver

Keywords : ODBC access
Version : WINDOWS:2.0
Platform : WINDOWS
Issue type :