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Subquery

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A Subquery is a query inside a query. In Oracle, you can make sub queries inside your main statements. The Outside query is called as main query and inner query is called as subquery.

These subqueries can exist in the WHERE clause, the From Clause and the SELECT clause, A subquery is basically a select statement which is used instead of another statement.

1: WHERE clause: Most frequently subquery will be start with the WHERE clause. These subqueries are also called Nested subqueries. There are 255 sub-queries in oracle.

2: FORM clause: Subqueries are also found in the FORM clause. These are called inline views.

3: SELECT clause:

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