Home Forums SQL Server 2008 SQL Server 2008 - General “SELECT 1″ rather than a “SELECT *” when using an EXISTS or a NOT EXISTS clause”. RE: “SELECT 1? rather than a “SELECT *” when using an EXISTS or a NOT EXISTS clause”.

  • February 10, 2011 at 5:45 am

    #1285100

    No difference. No matter what you use, it's removed early in the parsing stage. I use SELECT 1 to make it extremely clear that the exists is not returning any columns.

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

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