Question

I am trying to perform a join on two tables. One table contains the employee info and the other contains their degree info. The data type for the SSN in the employee table is varchar and contains hyphens. However, the data type for the SSN in the degree table is integer and does not contain any hyphens. The SSN is what I need to use to link the two tables. How can I accomplish a join with this setup?

Answer 1

I think the best solution is to convert string to an integer:

select <whatever>
from employee e join
     degree d
     on e.ssn = cast(replace(d.ssn, '-', '') as int)

Do note that transformations on the key probably mean that indexes will not get used. You should probably change the data type of one or the other to a consistent format.