Execute Dynamic SQL commands in SQL Server

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In some applications having hard-coded SQL statements is not appealing, because of the dynamic nature of the queries being issued against the database server. Because of this sometimes there is a need to dynamically create a SQL statement on the fly and then run that command. This can be done quite simply from the application perspective where the statement is built on the fly whether you are using ASP.NET , ColdFusion or any other programming language. But how do you do this from within a SQL Server stored procedure? SQL Server offers a few ways of running a dynamically built SQL statement. These ways are: Writing a query with parameters Using EXEC Using sp_executesql Writing a query with parameters This first approach is pretty straightforward if you only need to pass parameters into the WHERE clause of your SQL statement. Let’s say we need to find all records from the Customers table where City = ‘London’. This can be done easily as the following example shows. ...
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How To Delete a null record

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The code below will show you how exactly you delete a row with a NULL value. You can not use =NULL but you have to use IS NULL

CREATE TABLE #TestDeleteNull (id INT identity, SomeDate DATETIME)
INSERT #TestDeleteNull VALUES(GETDATE())
INSERT #TestDeleteNull VALUES(GETDATE())
INSERT #TestDeleteNull VALUES(NULL)


--Check what's in the table
SELECT * FROM #TestDeleteNull

--This won't work
DELETE #TestDeleteNull
WHERE SomeDate = NULL
--(0 row(s) affected)

--This is the way
DELETE #TestDeleteNull
WHERE SomeDate IS NULL
--(1 row(s) affected)

--Check again
SELECT * FROM #TestDeleteNull

Comments

Anonymous said…
great code. thanks.
February 12, 2009 at 4:25 AM
Unknown said…
thank a lot..it helped me
July 14, 2009 at 8:16 AM
Unknown said…
Thanks. It helped.
November 18, 2009 at 1:27 PM
Senthil kumar A. said…
thankfully gave a tips
March 22, 2010 at 4:58 PM
rduke131 said…
thanks a lotttttttttttttt.it helped me
November 8, 2010 at 8:32 AM
Unknown said…
Very Nice, Thanks A Lot...
December 24, 2010 at 3:58 AM
Richard Scott said…
Great help - thanks for being succinct and clear
September 9, 2011 at 10:49 AM
Richard Scott said…
Thanks - perfect for what I needed - I apprecaite you keepin it simple and succinct.
September 9, 2011 at 10:50 AM
Tejaswini said…
Thanks alot yar....
October 16, 2011 at 10:51 PM
OpenSAGA said…
Thank u so so much!!!!
November 22, 2011 at 11:23 AM
OpenSAGA said…
Thank u so so much!!!
November 22, 2011 at 11:23 AM
saravanan ramamoorthy said…
This comment has been removed by the author.
January 2, 2012 at 3:21 PM
Perma Frost said…
thanks alot! saved alot of time!
January 14, 2012 at 4:30 PM
JideshDavid said…
Thank u so much...
June 3, 2012 at 1:03 AM
JideshDavid said…
This comment has been removed by the author.
June 3, 2012 at 1:04 AM
J9139213 said…
Good Stuff - Thanks
September 11, 2012 at 7:26 AM
Unknown said…
thanks sir.....
July 16, 2013 at 4:43 AM
Mario B. said…
thanks for the advice, i was stuck
August 21, 2013 at 9:09 PM
Mario B. said…
thanks i was stuck
August 21, 2013 at 9:10 PM
Unknown said…
maarbanee bai jaan
May 31, 2014 at 6:12 AM
Unknown said…
Awesome piece of knowledge, thanks bro..It solved my issue in less than 5 min..Thanks for the great help.
July 10, 2014 at 6:36 AM
Unknown said…
Hi, This code is great, but it is deleating the whole line. What IF I Just want to Delete the NULL, and keep the rest of the row: For example in this code I would like to delete Null, but keep 't', AND 's'

CREATE TABLE #TestDeleteNull (id INT identity, SomeDate DATETIME, Comments text)
INSERT #TestDeleteNull VALUES(GETDATE(), 't' )
INSERT #TestDeleteNull VALUES(GETDATE(), 'f')
INSERT #TestDeleteNull VALUES(NULL, 't')
INSERT #TestDeleteNull VALUES(NULL, 's')



DELETE #TestDeleteNull
WHERE SomeDate IS NULL

SELECT * FROM #TestDeleteNull
July 23, 2014 at 7:42 AM
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