SQL delete query not working properly

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I found some duplicate records in my database table called Dwg_Register. Now I am running the following query to delete them.

SQL

Delete
FROM PIMS.dbo.Dwg_Register
WHERE
Dwg_Ref = 'NULL'; 
AND 
Title = 'NULL'; 
AND 
[Status] = 'Approved As Noted'

I can clearly see that there are 16 duplicate records found in the table having these fields mentioned in the above query repeating ... but when I execute this command in SQL server .. successfully executes but result is (0) records effected.

Can someone pls explain what is actually goin on in SQL server.

Thank you.

Posted 29-Aug-13 0:37am

rf_libra

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Comments

Hitesh Gohel 29-Aug-13 6:46am

Hi,
In your table fields Dwg_Ref,Title,[Status] which type of Data Type?

2 solutions

Solution 2

Hi ,

Please try this code

SQL

Delete
FROM PIMS.dbo.Dwg_Register
WHERE
Dwg_Ref = NULL; 
AND 
Title = NULL; 
AND 
[Status] = 'Approved As Noted'

Posted 29-Aug-13 0:49am

Hitesh Gohel

Comments

OriginalGriff 29-Aug-13 8:39am

Reason for my vote of one:
"Please try this code"
Did you? Please do, before you post...

"= NULL" is not the same as "IS NULL"

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OriginalGriff · Accepted Answer · 2013-08-29T00:45:00

Solution 1

Are you sure that the Dwg_Ref and Title columns actually contain the string value 'NULL'? If they contain actual null values, then they will not match, and the WHERE clause will fail. Perhaps you meant:

SQL

DELETE FROM PIMS.dbo.Dwg_Register
WHERE Dwg_Ref IS NULL AND Title IS NULL AND [Status] = 'Approved As Noted'

Posted 29-Aug-13 0:45am

OriginalGriff

Comments

Shobhana.n 29-Aug-13 8:27am

Agree....