SQL执行查询，然后根据结果执行另一个查询

Im trying to make a Database Migration SQL Script to transfer data from one database to another, the old database has about 10-15 tables the new one has in excess of 300, now im trying to do one big migration i know where eveything needs to go , I just cant figure out how to transfer based on the results.Im trying to make a Database Migration SQL Scri