I have two tables and after join these two table result should display on third table
table 1 table 2 table3 should be

U_id F_id U_id U_id F_id
u1 u2 u1 u1 u2
u1 u3 u2 u1 u3
u2 u3 u2 u3
u2 u1

and one condition for this is :: F_id of table 1 and U_id of table 2 is match then only it added in table 3 as above result of table 3.