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| SQL Server 2000 General discussion of Microsoft SQL Server -- for topics that don't fit in one of the more specific SQL Server forums. version 2000 only. There's a new forum for SQL Server 2005. |
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August 15th, 2006, 08:57 AM
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Registered User
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Conditional selecting
I am trying to write a query that pulls a variety of columns from several tables, but I'm stuck on some conditional logic. I am passing in a variable and want to pull back all records from the primary table that contain that variable. At the same time, I am trying to pull back data from a second table that is related to the first (a key is stored in the primary table, and text tied to the key is stored in the second). There are two possible columns to return from the secondary table. If the first column in null, then I want to return the second column. I don't really know how to do this. Can someone point me in the right direction? Thanks.
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August 15th, 2006, 09:04 AM
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Hi
You could look at the CASE statement in BOL. That might help you out.
Gert
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August 15th, 2006, 02:29 PM
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Also use THE COALEASE function or ISNULL function.
SELECT SomeColumn, ISNULL(ColA, ColB) FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
SELECT SomeColumn, COALESCE(ColA, ColB, '<no data>') FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
If ColB is null, "<no data>" is returned.
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August 16th, 2006, 12:21 PM
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Quote:
quote:Originally posted by Peso
Also use THE COALEASE function or ISNULL function.
SELECT SomeColumn, ISNULL(ColA, ColB) FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
SELECT SomeColumn, COALESCE(ColA, ColB, '<no data>') FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
If ColB is null, "<no data>" is returned.
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August 16th, 2006, 12:22 PM
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Registered User
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Join Date: Aug 2006
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Quote:
quote:Originally posted by Peso
Also use THE COALEASE function or ISNULL function.
SELECT SomeColumn, ISNULL(ColA, ColB) FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
SELECT SomeColumn, COALESCE(ColA, ColB, '<no data>') FROM SomeTable WHERE ColC = @MyVar
If ColA is not null, ColA is returned.
If ColA is null, ColB is returned.
If ColB is null, "<no data>" is returned.
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ISNULL was exactly what I was looking for! Thanks!
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