如何避免在内部连接查询中使用笛卡尔积?

I have 6 tables, let's call them a,b,c,d,e,f. Now I want to search all the colums (except the ID columns) of all tables for a certain word, let's say 'Joe'. What I did was, I made INNER JOINS over all the tables and then used LIKE to search the columns.I have 6 tables, let's call them a,b,c,d,e,f. N