VALUES(7)		PostgreSQL 9.2.24 Documentation		     VALUES(7)



NAME
       VALUES - compute a set of rows

SYNOPSIS
       VALUES ( expression [, ...] ) [, ...]
	   [ ORDER BY sort_expression [ ASC | DESC | USING operator ] [, ...] ]
	   [ LIMIT { count | ALL } ]
	   [ OFFSET start [ ROW | ROWS ] ]
	   [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ]

DESCRIPTION
       VALUES computes a row value or set of row values specified by value
       expressions. It is most commonly used to generate a "constant table"
       within a larger command, but it can be used on its own.

       When more than one row is specified, all the rows must have the same
       number of elements. The data types of the resulting table's columns are
       determined by combining the explicit or inferred types of the
       expressions appearing in that column, using the same rules as for UNION
       (see Section 10.5, "UNION, CASE, and Related Constructs", in the
       documentation).

       Within larger commands, VALUES is syntactically allowed anywhere that
       SELECT is. Because it is treated like a SELECT by the grammar, it is
       possible to use the ORDER BY, LIMIT (or equivalently FETCH FIRST), and
       OFFSET clauses with a VALUES command.

PARAMETERS
       expression
	   A constant or expression to compute and insert at the indicated
	   place in the resulting table (set of rows). In a VALUES list
	   appearing at the top level of an INSERT, an expression can be
	   replaced by DEFAULT to indicate that the destination column's
	   default value should be inserted.  DEFAULT cannot be used when
	   VALUES appears in other contexts.

       sort_expression
	   An expression or integer constant indicating how to sort the result
	   rows. This expression can refer to the columns of the VALUES result
	   as column1, column2, etc. For more details see ORDER BY Clause.

       operator
	   A sorting operator. For details see ORDER BY Clause.

       count
	   The maximum number of rows to return. For details see LIMIT Clause.

       start
	   The number of rows to skip before starting to return rows. For
	   details see LIMIT Clause.

NOTES
       VALUES lists with very large numbers of rows should be avoided, as you
       might encounter out-of-memory failures or poor performance.  VALUES
       appearing within INSERT is a special case (because the desired column
       types are known from the INSERT's target table, and need not be
       inferred by scanning the VALUES list), so it can handle larger lists
       than are practical in other contexts.

EXAMPLES
       A bare VALUES command:

	   VALUES (1, 'one'), (2, 'two'), (3, 'three');

       This will return a table of two columns and three rows. It's
       effectively equivalent to:

	   SELECT 1 AS column1, 'one' AS column2
	   UNION ALL
	   SELECT 2, 'two'
	   UNION ALL
	   SELECT 3, 'three';

       More usually, VALUES is used within a larger SQL command. The most
       common use is in INSERT:

	   INSERT INTO films (code, title, did, date_prod, kind)
	       VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');

       In the context of INSERT, entries of a VALUES list can be DEFAULT to
       indicate that the column default should be used here instead of
       specifying a value:

	   INSERT INTO films VALUES
	       ('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes'),
	       ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama', DEFAULT);

       VALUES can also be used where a sub-SELECT might be written, for
       example in a FROM clause:

	   SELECT f.*
	     FROM films f, (VALUES('MGM', 'Horror'), ('UA', 'Sci-Fi')) AS t (studio, kind)
	     WHERE f.studio = t.studio AND f.kind = t.kind;

	   UPDATE employees SET salary = salary * v.increase
	     FROM (VALUES(1, 200000, 1.2), (2, 400000, 1.4)) AS v (depno, target, increase)
	     WHERE employees.depno = v.depno AND employees.sales >= v.target;

       Note that an AS clause is required when VALUES is used in a FROM
       clause, just as is true for SELECT. It is not required that the AS
       clause specify names for all the columns, but it's good practice to do
       so. (The default column names for VALUES are column1, column2, etc in
       PostgreSQL, but these names might be different in other database
       systems.)

       When VALUES is used in INSERT, the values are all automatically coerced
       to the data type of the corresponding destination column. When it's
       used in other contexts, it might be necessary to specify the correct
       data type. If the entries are all quoted literal constants, coercing
       the first is sufficient to determine the assumed type for all:

	   SELECT * FROM machines
	   WHERE ip_address IN (VALUES('192.168.0.1'::inet), ('192.168.0.10'), ('192.168.1.43'));

	   Tip
	   For simple IN tests, it's better to rely on the list-of-scalars
	   form of IN than to write a VALUES query as shown above. The list of
	   scalars method requires less writing and is often more efficient.

COMPATIBILITY
       VALUES conforms to the SQL standard.  LIMIT and OFFSET are PostgreSQL
       extensions; see also under SELECT(7).

SEE ALSO
       INSERT(7), SELECT(7)



PostgreSQL 9.2.24		  2017-11-06			     VALUES(7)