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VALUES(7)                        SQL Commands                        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 appear-
       ing in that column, using the same rules as for UNION (see 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
              [select(7)].

       operator
              A sorting operator. For details see ORDER BY Clause [select(7)].

       count  The maximum number of rows to return. For details see LIMIT Clause [select(7)].

       start  The number of rows to skip before starting to return rows.  For details see LIMIT Clause [select(7)].

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
       [select(7)].

SEE ALSO
       INSERT [insert(7)], SELECT [select(7)]



SQL - Language Statements         2014-02-17                         VALUES(7)