Using the EXISTS Operator in SQL: A Comprehensive Guide

The EXISTS operator is used to test for the existence of any record in a subquery.

The EXISTS operator returns true if the subquery returns one or more records.

Syntax:

SELECT column_name(s)
FROM table_name
WHERE EXISTS
(SELECT column_name FROM table_name WHERE condition);

EmpId	EmpName	EmpAddress	EmpDept
1	Rambo	Kolkata	IT
2	Rohit	Kolkata	IT
3	Rohon	Kolkata	ITIS
4	Ronok	Kolkata	ITIS
5	Rubin	Kolkata	ITIS
6	Sorif	Kolkata	ADMIN
7	Soriful	Kolkata	ADMIN
8	Sofik	Kolkata	ADMIN

Example:

Code:

SELECT EmpName, EmpAddress
FROM Employee
WHERE EXISTS
(SELECT EmpId FROM Employee WHERE EmpName = 'Rambo')

Output:

The above code will produce the following result-

EmpName	EmpAddress
Rambo	Kolkata
Rohit	Kolkata
Rohon	Kolkata
Ronok	Kolkata
Rubin	Kolkata
Sorif	Kolkata
Soriful	Kolkata
Sofik	Kolkata