What is a self join? Explain it with an example?
Answer Posted / sanchit aggarwal(oracle dev.)
CREATE TABLE EMPLOYEE(
[EMPLOYEE_ID] INT PRIMARY KEY,
[NAME] NVARCHAR(50),
[MANAGER_ID] INT
)
GO
INSERT INTO EMPLOYEE VALUES(101,'Mary',102)
INSERT INTO EMPLOYEE VALUES(102,'Ravi',NULL)
INSERT INTO EMPLOYEE VALUES(103,'Raj',102)
INSERT INTO EMPLOYEE VALUES(104,'Pete',103)
INSERT INTO EMPLOYEE VALUES(105,'Prasad',103)
INSERT INTO EMPLOYEE VALUES(106,'Ben',103)
select e1.name from employee e1,employee e2
where e1.employee_id = e2.manager_id
Is This Answer Correct ? | 31 Yes | 12 No |
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