>>How know which records are (aren't) in another table?
>>Using SELECT query?
>>And when you need more than one criteria?
>
>First, let me make sure that I understood your question correctly. I assume that you have two almost identical tables and you want to retrieve records from table1 which are missed in table2. If it's really so, you run following query:
>Select * from Table1 ;
>Where Table1.Primarykey NOT IN (Select PrimaryKey From Table2)
Yes, I understand your point.
But, what I have to do, when I haven't absolutely identical tables?
And what is worse I haven't one Key.
I must seek in one table from another one by 3 or more related keys.

And query:
Select * from Table1 ;
where Table1.Key1+Table1.Key2+Table1.Key3 NOT IN ;
(Select Table2.Key1+Table2.Key2+Table2.Key3 From Table2)
is notsatisfactory for me.
Do you understand me?