T-SQL Case Statement in a JOIN ON Clause

Question

I am trying to build a case/if statement in a JOIN ON clause.

LEFT JOIN [CTSTRC] [Statuses] ON RIGHT([Statuses].[STRID], 3) = [CTE].[F61]
         


        

Answer 1

You're looking for IsNumeric but it doesn't always work (+,- and . are numeric) so you need to use the solution described by GBN which is to add .0e0 to your varchar

LEFT JOIN [CTSTRC] [Statuses] ON 
    (CASE WHEN ISNUMERIC(RIGHT([Statuses].[STRID], 3) + '.0e0) = 1 
          THEN  CAST(RIGHT([Statuses].[STRID], 3) AS INT) 
          ELSE 0  END) = [CTE].[F61]