Why Subquery Is Used In SQL?

Why is used in SQL query?

The SQL IN condition (sometimes called the IN operator) allows you to easily test if an expression matches any value in a list of values.

It is used to help reduce the need for multiple OR conditions in a SELECT, INSERT, UPDATE, or DELETE statement..

Which is better join or subquery?

The advantage of a join includes that it executes faster. The retrieval time of the query using joins almost always will be faster than that of a subquery. By using joins, you can maximize the calculation burden on the database i.e., instead of multiple queries using one join query.

Where can subqueries be used?

Explanation: SUBQUERIES can be used in the SELECT list and in the FROM, WHERE, and HAVING clauses of a query. The subquery (or subqueries) within a statement must be executed before the parent query that calls it, in order that the results of the subquery can be passed to the parent.

What is subquery and its types in SQL?

Type of Subqueries Single row subquery : Returns zero or one row. Multiple row subquery : Returns one or more rows. Multiple column subqueries : Returns one or more columns. Correlated subqueries : Reference one or more columns in the outer SQL statement.