Home Forums SQL Server 2005 T-SQL (SS2K5) Strange query gives strange results RE: Strange query gives strange results

  • September 6, 2013 at 7:32 am

    #1648072

    odepriester (9/6/2013)

    GilaMonster (9/6/2013)

    The filter is on the join and it's an outer join. So the filter is done before the join then the left join joins in the matching rows, while also returning any rows that don't match (definition of a left join)

    I thought about 3/4 times about what you said and I hadn't seen in my results that you were right.

    The fields from the description table are NULL when the rows don't match o.type = 'abcd'.

    Summary : I have just discovered a bug in the application :w00t:

    Thx

    You've discovered a small black hole in your understanding of how SQL joins work!

    Jokes aside, the query is fairly straightforward and from your description, is behaving exactly as it should.

    “Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw

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