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T SQL Joins

  • July 1, 2011 at 5:01 am

    #252940

    Hi,

    I have a simple query regarding joins, please see the examples below.

    The only difference between the examples is that in script a the join is made with b.key and in script b the join is from a.key. What I want to know is that does this make any difference at all??

    Script A

    select * from table_a a

    join table_b b on b.key = a.key

    Script B

    select * from table_a a

    join table_b b on a.key = b.key

  • July 1, 2011 at 6:57 am

    #1346997

    Nope, it does not.

    Seth Phelabaum

    Consistency is only a virtue if you're not a screwup. 😉

    Links: How to Post Sample Data[/url] :: Running Totals[/url] :: Tally Table[/url] :: Cross Tabs/Pivots[/url] :: String Concatenation[/url]

  • July 1, 2011 at 10:21 pm

    #1347396

    In the future, you can answer questions like this one for yourself by displaying the actual execution plans when you run the two queries. You should see identical joins in this instance.

    __________________________________________________

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  • July 4, 2011 at 2:47 am

    #1347675

    Thanks for your reply, I will bear that in mind.

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