![]() ![]() InterBase 2017 introduced support for CTE, InterBase 2020 Update 2 introduces support for recursive CTE. ![]() CTE's can help to simplify complex subqueries and joins, making the code more readable and easier to maintain. A Common Table Expression (CTE) returns a temporary result set than can be referenced in SELECT, INSERT, UPDATE, or DELETE statements. ![]() This is informally known as "common table expressions" although the SQL standard does not officially recognize that nomenclature. The query expression can be embedded directly in the SQL statement together with a correlation name used to identify the derived table.Īlternatively, query expressions named by an identifier can be listed in a clause that precedes the SQL statement and the named queries referenced by their identifiers in the SQL statement. A is a denoted in the form of a, which is evaluated to return the rows of the table. The derived table syntax enhances the abilities of existing applications to use InterBase as a backend RDMBS. Derived tables can shorten long queries, or break complex processes into logical steps. After initial usage, the terms are referenced in "un-angle bracket" form.ĭerived tables are temporary sets of records that can be used inside another queries. Please refer to that document for further definition of those terms. Note: Terms enclosed in angle brackets represent grammar production rules in the official SQL Standard document.
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