Question

Define dervied table

Answer 1

A derived table is a tableexpression that appears in the FROM clause of a query. You can apply derived tables when the use of column aliases is not possible because another clause is processed by the SQL translator before the alias name is known.

Answer 2

 · A derived table is a virtual table that is created within the scope of a query. The table is created with a SELECT statement of its own and is given an alias using the AS clause. It's contents can then be used within the query but become unavailable once the query has completed.