FROM Clause

The FROM clause of the SELECT statement lists table objects from which to retrieve data.

This syntax fragment is part of the SELECT statement.

^{(explicit id frocl002)
frocl002} ^{(explicit id frocl003)
frocl003} ^{(explicit id frocl004)
frocl004} ^{(explicit id frocl005)
frocl005} ^{(explicit id frocl007)
frocl007} ^{(explicit id frocl008)
frocl008} ^{(explicit id frocl010)
frocl010} ^{(explicit id tabx003)
tabx003} ^{(explicit id tabx001)
tabx001} ^{(explicit id frocl011)
frocl011} ^{(explicit id frocl012)
frocl012}

FROM Clause

FROM

{ | ( <ANSI Tables> { <ANSI Joins> ^[] } ) | { <ANSI Tables> <Other Tables> } [ ^[] , <Informix OUTER Join Clause> ^[] ] | [ <Lateral derived table> ^[] ] }

ANSI Tables

{ { { synonym | table | view | ONLY { (table ) | (synonym) } } } [ [ AS ] alias ^[] ] | { ^[] | <Collection Derived Table> ^[] | <Iterator> ^[] } }

Other Tables

{ { external } [ [ AS ] alias ^[] [ ( derived_column ) ] ] | ( ^[] <Collection Subquery> ) ^[] | ( subquery ) | { { table | view | synonym } | ^[] ONLY ( ^[] { table | synonym } ) ^[] } [ AS ] alias ^[] ( derived_column ) }


Element	Description	Restrictions	Syntax
`alias`	Temporary name for a table, view, or derived table in this query	See Aliases for Tables or Views.	Identifier
`derived _column`	Temporary name for a derived column in a table expression	Unless the underlying collection is a ROW type, you can declare no more than one `derived_column` name	Identifier
`external`	External table from which to retrieve data	Must exist, but cannot be the outer table in an outer join	Database Object Name
`subquery`	Nested query whose results are available to the outer query	See Table expressions	SELECT statement
`synonym, table, view`	Synonym for a table from which to retrieve data	Synonym and table or view to which it points must exist. Must include appropriate qualifiers.	Database Object Name

Every SELECT statement requires the FROM clause, whether or not any data source is required. If your query uses the database server to evaluate an expression that requires no data source, the FROM clause can reference any existing table in the current database on which you hold sufficient access privileges, as in the following example:

SELECT ATANH(SQRT(POW(4,2) + POW(5,2))) FROM systables;

¹ Informix® extension

² Must specify a supertable within a typed table hierarchy

³ See The ONLY Keyword

⁴ See Lateral derived tables

⁵ See Informix-Extension Outer Joins

⁶ See Iterator Functions

⁷ See Collection-Derived Table

⁸ See Collection Subquery

⁹ Informix® extension

¹⁰ See ANSI Joins

¹¹ See Aliases for Tables or Views