BUG: Command Aborted When Inserting into a IGNORE_DUP_KEY Table

• Microsoft SQL Server, version 6.5

SYMPTOMS

An attempt to insert duplicates into a table with the IGNORE_DUP_KEY option set ON may cause an INSERT INTO command to be aborted. The following scripts demonstrate this problem:

   SET NOCOUNT ON
   DROP TABLE t1
   GO
   DROP TABLE t2
   GO

   CREATE TABLE t1 (c INT)
   CREATE UNIQUE INDEX ind ON t1(c) WITH IGNORE_DUP_KEY

   SELECT c = 1
   INTO t2
   UNION ALL
   SELECT 1

   INSERT INTO t1(c)
      SELECT c
         FROM t2 WHERE NOT EXISTS (SELECT * FROM t1 WHERE t1.c = t2.c)

WORKAROUND

To work around this problem, do either of the following:

• INSERT with "DISTINCT" and "NOT EXISTS" clauses, as in the following example:

        INSERT INTO t1 (c)
           SELECT DISTINCT c
              FROM t2 WHERE NOT EXISTS (SELECT * FROM t1 WHERE t1.c = t2.c)
  
     -or-
  
  

• INSERT without using a "NOT EXISTS" clause, as in the following example:

        INSERT INTO t1 (c)
           SELECT c
              FROM t2
  
  

STATUS

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