I m passing a variable to stored procedure, i want the proc to make a look up to another table and get the primary key of the table and insert that value to the table.

Table A:
pk_id int,
user varchar

Table B:
userKey int

When i invoke sp_howto, and pass user to it, i want to it to get the pk_id from table A and insert it to table B userKey.

@res = select userKey from TableA where user=@user
insert into tableB (userKey) values (@res)

Does this work? and what if I have many keys I want to populate like this?