What is subquery in SQL and its types?


They help us target specific rows to perform various operations in SQL. They are used to SELECT, UPDATE, INSERT and DELETE records in SQL. There are different types of SQL subquery, like Single-row subquery, multiple row subquery, multiple column subquery, correlated subquery, and nested subquery.

How many types of subquery are there in SQL?

There are three broad types of a subquery in SQL. This chapter from OCA Oracle Database 11g: SQL Fundamentals I Exam Guide explains differences between a single-row subquery, multiple-row subquery and correlated subquery .

What are the two types of subqueries?

Types of Subqueries Single Row Sub Query: Sub query which returns single row output. They mark the usage of single row comparison operators, when used in WHERE conditions. Multiple row sub query: Sub query returning multiple row output. They make use of multiple row comparison operators like IN, ANY, ALL.

What is subquery in SQL?

A subquery is a query that is nested inside a SELECT , INSERT , UPDATE , or DELETE statement, or inside another subquery.

What are the two types of subqueries?

Types of Subqueries Single Row Sub Query: Sub query which returns single row output. They mark the usage of single row comparison operators, when used in WHERE conditions. Multiple row sub query: Sub query returning multiple row output. They make use of multiple row comparison operators like IN, ANY, ALL.

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