Question

Not sure if this is possible, but I have a field in a table which needs to be updated by a value from another table, but references a specific column e.g. if it’s 1 then get the value out of the [Jan] column etc.

Update table1
    Set Total = 
        CASE @count
            WHEN 1  THEN [Jan]
            WHEN 2  THEN [Feb]
            WHEN 3  THEN [Mar]
            WHEN 4  THEN [Apr]
            WHEN 5  THEN [May]
            WHEN 6  THEN [Jun]
            WHEN 7  THEN [Jul]
            WHEN 8  THEN [Aug]
            WHEN 9  THEN [Sep]
            WHEN 10 THEN [Oct]
            WHEN 11 THEN [Nov]
            WHEN 12 THEN [Dec]
        END
    from table2

Thanks in advance

Answer 1

Update t
    Set t.Total = 
        CASE @count
            WHEN 1  THEN t2.[Jan]
            WHEN 2  THEN t2.[Feb]
            WHEN 3  THEN t2.[Mar]
            WHEN 4  THEN t2.[Apr]
            WHEN 5  THEN t2.[May]
            WHEN 6  THEN t2.[Jun]
            WHEN 7  THEN t2.[Jul]
            WHEN 8  THEN t2.[Aug]
            WHEN 9  THEN t2.[Sep]
            WHEN 10 THEN t2.[Oct]
            WHEN 11 THEN t2.[Nov]
            WHEN 12 THEN t2.[Dec]
        END
    from table1 t inner join table2 t2 
    on t.ID = t2.ID --your condition