INF: Assignment of Empty Results Set Does Not Set Variable

ID: Q107561

The information in this article applies to:

Microsoft Windows NT versions 3.1, 3.5, 3.51, 3.51 SP2, 3.51 SP5, 4.0, 4.0 Service Pack 6, 4.0 Service Pack 6a, 4.0 SP4, 5.0, SP3
Microsoft SQL Server version 4.2x

SUMMARY

If a local variable is set by the results of a SELECT statement which returns no rows, the value currently stored in the local variable will remain unchanged.

MORE INFORMATION

An example of this behavior would be the following statement:


   declare @var int
   select @var = 5
   select @var = dbid from sysdatabases where name = "does not exist"
   select @var

The above query will return 5 as the results of the final SELECT statement. However, if a local variable is set by a query which explicitly returns NULL, the value of the local variable will be set to NULL.

Additional query words: 4.20 Transact-SQL

Keywords : kbother SSrvTrans kbNTOS310 kbNTOS350 kbNTOS351 kbNTOS400 kbNTOS400sp1 kbNTOS400sp2 kbNTOS500sp3 kbNTOS400sp4 kbNTOS400sp6 kbNTOS400sp5
Version : winnt:3.1,3.5,3.51,3.51 SP2,3.51 SP5,4.0,4.0 SP4,4.0 Service Pack 6,4.0 Service Pack 6a,4.2x,5.0,SP3
Platform : winnt
Issue type :