Self join

SELF JOIN is used to compare the table itself.

There is no any keyword “SELF” exists in SQL server.

LEFT/RIGHT/FULL keywords we can use for the self-join query. Here the LEFT and RIGHT tables both are same.

Syntax:

SELECT column_name(s)
FROM table1 t1
JOIN table1 t2
ON t1.column_name=t2.column_name; 

Example:

SELECT E.EmpID, E.EmpName, E.DeptID, E1.EmpName FROM tbl_Employees E  

[LEFT/RIGHT/INNER]JOIN tbl_Employees E1

ON E1.EmpID=E.ManagerID

Result