MySQL Sub Query with Exists and Not Exists

MySQL Sub Query:

MySQL Sub Query is a query nested within another query such as SELECT, INSERT, UPDATE or DELETE.

MySQL Sub Query with Exists and Not Exists:

When a subquery is used with the EXISTS or NOT EXISTS operator, a subquery returns a Boolean value of TRUE or FALSE.

MySQL Sub Query Syntax:

MySQL Exists Syntax:

MySQL Not Exists Syntax:

Sample Table:

MySQL Sub Query on Sample Table:

MySQL EXISTS Operator on Sample Table:

• If cn_name (London) exists in the city table, then it will fetch all data of the field (name) contained in the student table.

MySQL NOT EXISTS Operator on Sample Table:

• If cn_name (England) not exists in the city table, then it will fetch all data of the field (name) contained in the student table.