Home Forums SQL Server 2012 SQL Server 2012 - T-SQL How to do a Lookup from one Database Table to another Database Table and replace 1 columns results RE: How to do a Lookup from one Database Table to another Database Table and replace 1 columns results

  • March 24, 2017 at 2:04 pm

    #1934869

    earlysunrirse - Friday, March 24, 2017 11:12 AM

    Hi,
    try the code below::

    update dbo.User_table
    Set Department = case
    when y.Department = w.DeptCode then w.DeptReportName
    else NULL
    END
    from dbo.User_table y inner join New_Department w on y.Department=w.Deptcode

    Regards
    Anna

    This uses two different instances of dbo.User_Table: one aliased "y" and the other unaliased.  This may not (and probably WILL not) produce the results that you are expecting.

    Also, the CASE expression is unnecessary in this statement, because the join conditions are exactly the same as the CASE conditions, so only the first condition will ever be met.  The CASE expression would still be unnecessary even if you changed the JOIN to a LEFT OUTER JOIN.

    Drew

    J. Drew Allen
    Business Intelligence Analyst
    Philadelphia, PA