Question

Is it possible to use only several starting characters of a field value as a base of case statement in a SQL Server stored procedure?
For example, I need to update a field in a table according to the first three characters in another field of the same table:

UPDATE Table1
SET Field1 = CASE 
             WHEN ??? = 'vl1' THEN '01'
             WHEN ??? = 'vl2' THEN '02'
             WHEN ??? = 'vl3' THEN '03' 
             '''''
END

How could I use the first three characters of a Field2 value instead of ??? ?

Answer 1

Use SUBSTRING

UPDATE Table1
SET Column1 = CASE SUBSTRING(Column2,1,3)
             WHEN 'vl1' THEN '01'
             WHEN 'vl2' THEN '02'
             WHEN 'vl3' THEN '03' 
             '''''
END

(I’ve switched to a simple CASE expression since that’s all we need here, and switched terminology too)