Chapter 14. Using Subqueries to Define Unknown Data
During this hour, you are presented with the concept of using subqueries to return results from a database query more effectively.
The highlights of this hour include:
What a subquery is
The justifications of using subqueries
Examples of subqueries in regular database queries
Using subqueries with data manipulation commands
Embedded subqueries
What Is a Subquery?
A subquery, also known as a nested query, is a query embedded within the WHERE clause of another query to further restrict data returned by the query. A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. Subqueries are used with the SELECT, INSERT, UPDATE, and DELETE ...
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