...I have 4 tables wich have almost the same fields (one of them has some field in plus). For interogate this tables I try to use inner join, but I without succesful. I see the tutorial for 2 table but when I try with 4 tables don't work.
In this tables exist one field (COMM) wich is in all tables, and I want to see all records wich have the same value in COM fields.
Could you show me a SQL code for this my situation? Belive me please, before to ask this, I try to do my self...but, maybe is to hard for me...

thanks and the best regards!