Dumb sql question

This is a dumb sql question on an update statement. I have two tables. Both contain a ssn and a user id. One table may contain more than one ssn and user id if the user has more than on user id. I don't care which user id I update into the first table, I just want any user id that matches the ssn. so Table 1 PI1 Table 2 IDENT PI1_SSN IDENT_SSN PI1_USER_ID IDENT_USER_ID If I use the following syntax, I get the message that the subquery has returned more than one row. I thought that was what the "in" was for instead of the "=". Here is the statement I am using. update PI1 set PI1_USER_ID = (select IDENT_USER_ID from ident) where PI1_USER_ID is null and pi1_ssn in (select ident_ssn from ident); I have re-arranged the subqueries into different parts. Like I said, I realize that I will not know which user ID I get updated into the PI1 table. I don't care. I just wany any of the users' user ID. Thanks SDowdy@uh.edu