A SQL derived table is created with a derived table expression consisting of a nested select statement, as in the following example, which returns a list of cities in the publishers table of the pubs2 database:
select city from (select city from publishers) cities
The SQL derived table is named cities and has one column titled city. The SQL derived table is defined by the nested select statement and persists only for the duration of the query, which returns the following:
city -------------------- Boston Washington Berkeley
