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poptart007
Starting Member
1 Post |
 Posted - 2003-04-29 : 10:34:20
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| Just wondering if anyone knows how to implement a constraint to ensure that a yes/no choice is only available to the user.ThanksEdited by - merkin on 04/29/2003 10:38:30 |
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ValterBorges
Master Smack Fu Yak Hacker
1429 Posts |
Posted - 2003-04-29 : 10:50:26
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| use a bit field.or on a character field use trigger to check at the time of insertion if it's yes/noorCREATE TABLE test ( test_id int PRIMARY KEY, answer char(3), CONSTRAINT answer CHECK (answer IN ('yes','no') )Edited by - ValterBorges on 04/29/2003 10:52:39 |
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jsmith8858
Dr. Cross Join
7423 Posts |
Posted - 2003-04-29 : 12:19:16
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quote:
on a character field use trigger to check at the time of insertion if it's yes/no
Are CHECK constraints considered triggers? I assume they have less overhead than a regular triggers?- Jeff |
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ValterBorges
Master Smack Fu Yak Hacker
1429 Posts |
Posted - 2003-04-29 : 12:50:42
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FROM BOLquote:
Constraints allow you to define the way Microsoft® SQL Server™ 2000 automatically enforces the integrity of a database. Constraints define rules regarding the values allowed in columns and are the standard mechanism for enforcing integrity. Using constraints is preferred to using triggers, rules, and defaults. The query optimizer also uses constraint definitions to build high-performance query execution plans.
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jsmith8858
Dr. Cross Join
7423 Posts |
Posted - 2003-04-29 : 13:25:57
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oops. didn't see the 'OR' between the comment about using a trigger and then the check constraint. I thought you were implying the CHECK constraint is a trigger.Never mind! - Jeff |
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Constraints in SQL