The World’s Leading Microsoft .NET Magazine
   
 
timstall

Donate Today!

Search Box

 

Calendar

««May 2008»»
SMTWTFS
     123
45678910
11
12
13
14
15
1617
18192021222324
25262728293031

My Top Tags

                                       

Mailing List

My RSS Feeds








Cloning a temp table schema in SQL

posted Wednesday, 8 August 2007

SQL temp tables can be a functional and performance life-saver because they let you store intermediate results. You can then do resource-heavy calculations on this smaller result set, or just break a complex procedure into multiple, easier-to-handle parts.  Sometimes you'll have two temp tables with the same schema. SQL provides as easy way to clone a temp table (thanks to our Paylocity SQL architect for showing me this). Here's a sample:

CREATE TABLE #Main1 --prePaging
(
  colInt int,
  colString varchar(20)
)

Insert Into #Main1 Values(10, 'aaa')
Insert Into #Main1 Values(20, 'bbb')
Insert Into #Main1 Values(30, 'ccc')

--Dynamically create a close of #Main1, call it #Main2
--This doesn't touch data
Select * Into #Main2 From #Main1 Where 1=2

--show that Main2 exists, and has the right schema
Select * From #Main1
Select * From #Main2

--Now insert some data into Main2
Insert Into #Main2 (colInt, colString) Values(40, '
ddd')
Select * From #Main2

drop table #Main1
drop table #Main2

The key is the line "Select * Into #Main2 From #Main1 Where 1=2", which dynamically creates table Main2 and sets its columns equal to that of Main1.

 


Living in Chicago and interested in working for a great company? Check out the careers at Paylocity.

tags:  

links: digg this    technorati