Question

Im having the following table , each employee have a manager, if a guy is his own manager den the managerid field is null, i want emid name and manager id as result table name is employee

emid name managerid
1    raj  null
2    ram   1
3    ravi   null
4    arvind  3
5    rithu   2

and i want the result as

emid name managername
1    raj  raj
2    ram   raj
3    ravi   ravi
4    arvind  ravi
5    rithu   ram

Answer 1

SELECT e1.emid, e1.name, COALESCE(e2.name, e1.name) AS managername
    FROM employee e1
        LEFT JOIN employee e2
            ON e1.managerid = e2.emid