Question

I have data in a MSSQL table (TableB) where [dbo].tableB.myColumn changes format after a certain date…

I’m doing a simple Join to that table..

Select [dbo].tableB.theColumnINeed from [dbo].tableA  left outer join [dbo].tableB on [dbo].tableA.myColumn = [dbo].tableB.myColumn 

However, I need to join, using different formatting, based on a date column in Table A ([dbo].tableA.myDateColumn).

Something like…

Select [dbo].tableB.theColumnINeed from [dbo].tableA  left outer join [dbo].tableB on [dbo].tableA.myColumn =      IF [dbo].tableA.myDateColumn > '1/1/2009'         BEGIN             FormatColumnOneWay([dbo].tableB.myColumn)         END     ELSE         BEGIN             FormatColumnAnotherWay([dbo].tableB.myColumn)         END 

I’m wondering if there’s a way to do this.. or a better way I’m not thinking of to approach this..

Answer 1

SELECT [dbo].tableB.theColumnINeed FROM   [dbo].tableA  LEFT OUTER JOIN [dbo].tableB ON [dbo].tableA.myColumn =     CASE     WHEN [dbo].tableA.myDateColumn <= '1/1/2009' THEN FormatColumnOneWay([dbo].tableB.myColumn)     ELSE FormatColumnAnotherWay([dbo].tableB.myColumn)    END