Underforespørsler
Underforespørsler, also known as subqueries, are a fundamental concept in SQL (Structured Query Language), a standard language for managing and manipulating relational databases. A subquery is a query nested within another query. It can be used in various clauses of the SELECT statement, including the SELECT, FROM, WHERE, and HAVING clauses, as well as in the INSERT, UPDATE, and DELETE statements.
Subqueries are particularly useful for performing operations that require multiple steps or conditions. They can be
One of the key advantages of using subqueries is their ability to simplify complex queries by breaking
In summary, underforespørsler are an essential feature of SQL that allow for the nesting of queries within