Subquery

External Article

Three Use Case Examples for SQL Subqueries

  • Article

There are many great tutorials on syntax, performance, and keywords for invoking subqueries. However, I wish to discover a tip highlighting selected SQL subquery use cases. Please briefly describe three SQL subquery use case examples. For each use case, cover how a subquery interacts with outer queries and the T-SQL for implementing the use case. Review excerpts from each example to show the value of implementing the use case.

2023-04-14

Stairway to T-SQL Beyond The Basics

Stairway to T-SQL: Beyond The Basics Level 3: Building a Correlated Subquery

  • Stairway Step

This stairway level will expand on the subquery topic by discussing a type of subquery known as a correlated subquery, and explores what a correlated subquery is and how it is different from a normal subquery.

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2019-05-08 (first published: )

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Question of the Day

Creating a JSON Document II

I want to create a JSON document that contains data from this table:

TeamID TeamNameCity         YearEstablished
1      Cowboys  Dallas       1960
2      Eagles   Philadelphia 1933
3      Packers  Green Bay    1919
4      Chiefs   Kansas City  1960
If I run this code, what document(s) is/are returned?
SELECT json_objectagg( n.city : n.TeamName)
FROM dbo.NFLTeams n;

See possible answers