Self Join in SQL

The SELF JOIN is used to join the table to itself that why it is known as SELF JOIN.

Syntax:

SELECT columnList FROM table1 t1, table1 t2 WHERE t1.commonColumn = t2. commonColumn;

Example:

SELECT emp1.EMP_NAME FROM EMPLOYEE emp1, EMPLOYEE emp2 
WHERE emp1.AGE = emp2.AGE;

Output:

EMP_NAME
Parmender
Nidhi
Parmender
Parbhjot
Parmender
Nidhi
Parmender
Parbhjot
Parmender
Nidhi