I have given two examples. Those are self and inner join.
SQL Query Inner Join
FROM (TEST.EMP E JOIN
D.DEPTNO = E.WORKDEPT) JOIN
ON EMPNO = RESPEMP;
The above is the best example for finding match in 3 tables using Inner join.
SQL Query Self-Join
A.ADMRDEPT,A.DEPTNAMEFROM TEST.DEPT A
WHERE A.ADMRDEPT =A.DEPTNO;
The above SQL query is the best example for self join.