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How to determine if an index already exists for a table?

Posted on 2006-07-08
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Last Modified: 2012-06-21
Hi... I have a table which I want to programmatically create a clustered index using the following statement:

ALTER TABLE tBooks ADD CONSTRAINT PK_BookNbr PRIMARY KEY CLUSTERED (BookNbr)

which works just fine.  Now, I want to check if the index already exists before I issue the command again (from within a C# program).  I was using the following command:

SELECT name FROM sysindexes WHERE name = 'PK_BookNbr'

but it doesn't find the existing index and tries to re-create it.

What is the proper syntax to see if the index already exists in a table?

Thanks for your help in advance.
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Question by:rmmarsh
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Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 17066210
the PRIMARY KEY is a constraint, so you have to look here:
SELECT name FROM sysconstraints WHERE name = 'PK_BookNbr'

there will also be an entry in sysindexes, but with a system-generated name
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Author Comment

by:rmmarsh
ID: 17066229
When I run the SELECT statement in the SQL Server Manager, I get an error saying:

 invalid column name 'name'

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Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 17066240
sorry:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_sys-c_8f77.asp

SELECT object_name( constid) FROM sysconstraints WHERE object_name(id) = 'PK_BookNbr'
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Author Comment

by:rmmarsh
ID: 17066293
nope... that's not it either... nothing is returned from that command

My command -> SELECT name FROM sysindexes WHERE name = 'PK_BookNbr'
works, and shows the name.  However, when I run it in the program, it returns no rows (it should return 1 row)...
 
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Author Comment

by:rmmarsh
ID: 17066295
...works, and shows the name (in the SQL Server Manager).
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Accepted Solution

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Guy Hengel [angelIII / a3] earned 500 total points
ID: 17066368
> However, when I run it in the program, it returns no rows
are you connected to the correct database?

SELECT name FROM <yourdatabase>.dbo.sysindexes WHERE name = 'PK_BookNbr'
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Author Comment

by:rmmarsh
ID: 17066400
Ahhh... thank you so much... forgot about that small item  :D
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