Q108685

• Microsoft SQL Server Programmer's Toolkit, version 4.2

SYMPTOMS

When calling DB-Library function dbcursorfetch with the FETCH_NEXT option in a medium-model MS-DOS application, the function call fails, generating error 221:

Column of type (%s) does not allow nulls. It may not be compared with null.

CAUSE

When building the query to perform the cursor fetch, DB-Library is incorrectly attempting to compare a NOT NULL column with the value NULL.

WORKAROUND

For MS-DOS programs, use the large-model DB-Library. The function dbcursorfetch behaves correctly on other operating systems.

STATUS

Microsoft has confirmed this to be a problem in DB-Library version 4.20.50. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: db-lib dblib cursors

Keywords : kbprogramming
Issue type :
Technology : kbSQLServSearch kbAudDeveloper kbSQLServPTK420