BUG: Update of Text Field Using CASE Can Generate AV

• Microsoft SQL Server versions 6.0, 6.5

SYMPTOMS

If you update a text field using a CASE in the UPDATE statement, an access violation is generated.

WORKAROUND

Avoid using CASE in UPDATE statements that modify text columns.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SQL Server versions 6.0 and 6.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following scenario will demonstrate this problem.

create table tbl1(col1 int null, col2 text null, col3 int)
go
insert into tbl1 values (1, 'hello', 1)
go
update tbl1 set col2 = case when (col1 is null) then col2
                            else null
                            end 

Additional query words: sql6

Keywords          : kbprg SSrvProg kbbug6.50 kbbug6.00 
Version           : 6.0 6.5
Platform          : WINDOWS 
Issue type        : 

Last Reviewed: March 26, 1999