Left join not pulling all from left table

  • T has 57,000 distinct rows

    Z has over a million.  I did row over partition on the key field (Z.zpsh)

    When i run the following SQL, I only get 47,000 rows back.

    Shouldn't I get 57,000?   thanks

     

    select * from #temp1 T

    left join #temp2 Z

    on T.entry = Z.zpsh

    where z.rownumber = 1

  • What do you mean by this?

    T has 57,000 distinct rows

    I mean, why did you use the word 'distinct'?

     

    The absence of evidence is not evidence of absence.
    Martin Rees

    You can lead a horse to water, but a pencil must be lead.
    Stan Laurel

  • By including Z in the where clause you've effectively turned it into an inner join.

  • No, your WHERE clause is likely filtering the rows.

     

    Without the actual SQL statement, and some sample data, that's an educated guess.

    Michael L John
    If you assassinate a DBA, would you pull a trigger?
    To properly post on a forum:
    http://www.sqlservercentral.com/articles/61537/

  • I used "distinct" to make it clear that I had no duplicate values.

     

     

  • For an OUTER JOIN, you must put conditions on the possibly-missing table in the JOIN clause, not in the WHERE clause.

    select * from #temp1 T

    left join #temp2 Z

    on T.entry = Z.zpsh

    and z.rownumber = 1

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

  • That was it!!!  I actually printed your reply and pinned it to my cube!!!!!!!!!!

    Thanks so much

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