Microsoft KB Archive/105337
Article ID: 105337
Article Last Modified on 12/3/2003
- Microsoft SQL Server 4.21a Standard Edition
- Microsoft SQL Server 6.0 Standard Edition
- Microsoft SQL Server 6.5 Standard Edition
- Microsoft SQL Server 4.2 for OS/2
This article was previously published under Q105337
BUG# OS/2: 1777 (4.2a) NT: 505 (4.2), 14895 (6.0/6.5)
On page 226 of the "Transact-SQL Reference" for SQL Server for Windows NT (or page 69 of the "Language Reference Guide" for OS/2), it states:
If IGNORE_DUP_KEY is set and you give an UPDATE or INSERT statement that creates duplicate keys, the row that causes the duplicates is not added or changed. In fact, in the case of UPDATE , the row is discarded.
...However, if the UPDATE or INSERT attempt affects multiple rows, the other rows are added or changed as usual.
When an UPDATE is performed, SQL Server does not behave as explained above. Instead, the UPDATE fails if it will cause a duplicate row in the table.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
For example, table test (name char(10), age int NULL) has a unique clustered key with IGNORE_DUP_KEY on column age:
Name Age ---------------------- karl 19 smith 20 johns 24 mary 25
The following query:
update test set age=age+4 where name not like "%johns%"
fails with the errors:
According to the manual, it should discard the row smith and update the other two rows (karl and mary) as in the following:
name age -------------------- karl 23 johns 24 mary 29
Additional query words: update duplicates Windows NT
Keywords: kbbug kbprogramming kbpending KB105337