ORACLE EXISTS

In Oracle, exists clause is used with select, insert, update, delete statements. It is used to combine the queries and creating subquery.

Syntax

Where exists (subquery)  

Parameters

subquery: It is a select statement which returns at least one record set.

Table 1:

Table 1:

Example 1

Query: select name from table1 where exists (select *from table2 where table1.id=table2.id)

Example 2

Query: select id, salary from table2 where exists (select *from table1 where table2.id=table1.id)

Example 3

Query: select * from table1 where not exists (select *from table2 where table1.id=table2.id)