You are here: parentheses in a check constraint « MsSQL Server « IT news, forums, messages
parentheses in a check constraint

Posted by Helen Wheels on 06/10/07 01:39

Can we use parentheses in a check constraint in MS-SQL-server DDL?

e.g. I'm having a problem with the following statement:

ALTER TABLE [dbo].[MyTable] ADD CONSTRAINT [CK_MyTable_TimesDataOK]
CHECK (([TimeOn] IS NULL AND [TimeOff] IS NULL)
OR
([ShiftCode] IS NOT NULL AND [TimeOn] IS NOT NULL AND [TimeOff] IS NOT
NULL));

The statement appears to run fine, but when I look at my table
definition afterwards, it appears that SQL-server ignored the
parentheses in my constraint; it shows the constraint expression as:
(([TimeOn] IS NULL AND [TimeOff] IS NULL OR [ShiftCode] IS NOT NULL AND
[TimeOn] IS NOT NULL AND [TimeOff] IS NOT NULL))

My intention is that if there's (non null) data in either of the columns
TimeOn or TimeOff is not null, all three of the columns TimeOn, TimeOff
and ShiftCode must have non null data.

OK, I realise I could enforce this by altering my table setup in other
ways. Right now I'm just trying to figure out if this I'm just up
against a difference between dialects of SQL in check constraints here.
Am I missing something obvious with parentheses?

BTW the DDL for the table I'm testing on:
CREATE TABLE [dbo].[MyTable](
[FNname] [nvarchar](50) NOT NULL,
[ShiftDate] [datetime] NOT NULL,
[ShiftCode] [nchar](2) NULL,
[TimeOn] [nchar](4) NULL,
[TimeOff] [nchar](4) NULL);

 

Navigation:

[Reply to this message]


Удаленная работа для программистов  •  Как заработать на Google AdSense  •  England, UK  •  статьи на английском  •  PHP MySQL CMS Apache Oscommerce  •  Online Business Knowledge Base  •  DVD MP3 AVI MP4 players codecs conversion help
Home  •  Search  •  Site Map  •  Set as Homepage  •  Add to Favourites

Copyright © 2005-2006 Powered by Custom PHP Programming

Сайт изготовлен в Студии Валентина Петручека
изготовление и поддержка веб-сайтов, разработка программного обеспечения, поисковая оптимизация