How to get the second joining table data which is not come in combined condition of first and second table ?

[amskape]

Dear Friends,

I have 2 tables in Postgresql. Table1 and Table2 .... There is a common field Table1.ARN and Table2.RN . My need is get all the data of second table which is not in the common data get by Table1.ARN=Tabl e2.RN.

Waiting your fast reply

Thanks

Anes P A