What is a self join?

Self join is join which is join against equality-Like Employee Id is the Id of Manager Select E.Name as E,M.Name as M from Emp Where E.id=M.id where

Just in case, if they ask you to write query.... TableName: T1, Columns: EId, EName, MId select E1.EId as EmployeeId, E1.Ename as EmployeeName, E2.EName as ManagerName from T1 as E1, T1 as E2 where E1.MId = E2.EId

Self join is just like any other join, except that two instances of the same table will be joined in the query. Here is an example: Employees table which contains rows for normal employees as well as managers. So, to find out the managers of all the employees, you need a self join.