Solved

Select with case in a "WHERE"

Posted on 2014-09-19
2
164 Views
Last Modified: 2014-09-19
I'm trying to run a select statement and want the where clause to use different criteria depending on the value of a variable.  When I run the below I get an error
     Msg 102, Level 15, State 1, Line 9
     Incorrect syntax near '='.

Can I not do that in a where clause?


declare @Itemtype varchar(1)
set @Itemtype='1'

select 'pop30110',iv1.*
from pop30110 iv1
join dynamics_ext.dbo.tmpinvalid tmp on tmp.itemnmbr=iv1.itemnmbr
--where tmp.itemtype=@itemtype
--where tmp.itemtype ='1'
where (case when @Itemtype='' then tmp.itemtype ='1' else tmp.itemtype=@itemtype end )
0
Comment
Question by:jdr0606
2 Comments
 
LVL 34

Accepted Solution

by:
Brian Crowe earned 500 total points
ID: 40333864
select 'pop30110',iv1.*
from pop30110 iv1
join dynamics_ext.dbo.tmpinvalid tmp on tmp.itemnmbr=iv1.itemnmbr
WHERE (@itemtype = '' AND tmp.itemtype = '1')
   OR (@itemtype <> '' AND tmp.itemtype = @itemtype)
0
 
LVL 69

Expert Comment

by:Scott Pletcher
ID: 40333879
Much better query optimization by just making sure that @itemtype is never '':

declare @Itemtype varchar(1)
 set @Itemtype='1'
if @Itemtype = ''
    set @Itemtype = '1'

select ...
where tmp.itemtype = @itemtype
0

Featured Post

Back Up Your Microsoft Windows Server®

Back up all your Microsoft Windows Server – on-premises, in remote locations, in private and hybrid clouds. Your entire Windows Server will be backed up in one easy step with patented, block-level disk imaging. We achieve RTOs (recovery time objectives) as low as 15 seconds.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
sql 2014,  lock limit 5 32
sql server computed columns 11 31
Help Required 3 97
divide by zero error 23 16
Why is this different from all of the other step by step guides?  Because I make a living as a DBA and not as a writer and I lived through this experience. Defining the name: When I talk to people they say different names on this subject stuff l…
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Via a live example, show how to backup a database, simulate a failure backup the tail of the database transaction log and perform the restore.
Viewers will learn how the fundamental information of how to create a table.

778 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question