Which one is not a type of subquery ?OptionsSingle row sub queryMultiple row sub queryCorrelated Sub queryVariation based Sub query

Break Down the Problem

1. Identify the types of subqueries mentioned in the options.
2. Determine which of the options is not a recognized type of subquery.

Relevant Concepts

1. Single row subquery: Returns only one row from the result set.
2. Multiple row subquery: Can return multiple rows from the result set.
3. Correlated subquery: Depends on the outer query for its values; executed for each row processed by the outer query.
4. Variation based subquery: This term does not represent any standard or recognized type of subquery in SQL.

Analysis and Detail

• Single row subquery: Used with operators like =, <, >, etc.
• Multiple row subquery: Commonly used with operators like IN, ANY, ALL.
• Correlated subquery: Involves a relationship between the outer query and the subquery.
• Variation based subquery: This is not a standard term used in SQL documentation or practice.

Verify and Summarize

Upon reviewing standard SQL subquery classifications, the term "Variation based subquery" does not correspond to any recognized type.

Final Answer

Variation based Sub query is not a type of subquery.