VALUES(7)

1VALUES(7)               PostgreSQL 9.2.24 Documentation              VALUES(7)
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NAME

6       VALUES - compute a set of rows
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SYNOPSIS

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

16       VALUES computes a row value or set of row values specified by value
17       expressions. It is most commonly used to generate a “constant table”
18       within a larger command, but it can be used on its own.
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20       When more than one row is specified, all the rows must have the same
21       number of elements. The data types of the resulting table's columns are
22       determined by combining the explicit or inferred types of the
23       expressions appearing in that column, using the same rules as for UNION
24       (see Section 10.5, “UNION, CASE, and Related Constructs”, in the
25       documentation).
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27       Within larger commands, VALUES is syntactically allowed anywhere that
28       SELECT is. Because it is treated like a SELECT by the grammar, it is
29       possible to use the ORDER BY, LIMIT (or equivalently FETCH FIRST), and
30       OFFSET clauses with a VALUES command.
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PARAMETERS

33       expression
34           A constant or expression to compute and insert at the indicated
35           place in the resulting table (set of rows). In a VALUES list
36           appearing at the top level of an INSERT, an expression can be
37           replaced by DEFAULT to indicate that the destination column's
38           default value should be inserted.  DEFAULT cannot be used when
39           VALUES appears in other contexts.
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41       sort_expression
42           An expression or integer constant indicating how to sort the result
43           rows. This expression can refer to the columns of the VALUES result
44           as column1, column2, etc. For more details see ORDER BY Clause.
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46       operator
47           A sorting operator. For details see ORDER BY Clause.
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49       count
50           The maximum number of rows to return. For details see LIMIT Clause.
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52       start
53           The number of rows to skip before starting to return rows. For
54           details see LIMIT Clause.
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NOTES

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

65       A bare VALUES command:
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67           VALUES (1, 'one'), (2, 'two'), (3, 'three');
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69       This will return a table of two columns and three rows. It's
70       effectively equivalent to:
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72           SELECT 1 AS column1, 'one' AS column2
73           UNION ALL
74           SELECT 2, 'two'
75           UNION ALL
76           SELECT 3, 'three';
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78       More usually, VALUES is used within a larger SQL command. The most
79       common use is in INSERT:
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81           INSERT INTO films (code, title, did, date_prod, kind)
82               VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');
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84       In the context of INSERT, entries of a VALUES list can be DEFAULT to
85       indicate that the column default should be used here instead of
86       specifying a value:
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88           INSERT INTO films VALUES
89               ('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes'),
90               ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama', DEFAULT);
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92       VALUES can also be used where a sub-SELECT might be written, for
93       example in a FROM clause:
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95           SELECT f.*
96             FROM films f, (VALUES('MGM', 'Horror'), ('UA', 'Sci-Fi')) AS t (studio, kind)
97             WHERE f.studio = t.studio AND f.kind = t.kind;
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99           UPDATE employees SET salary = salary * v.increase
100             FROM (VALUES(1, 200000, 1.2), (2, 400000, 1.4)) AS v (depno, target, increase)
101             WHERE employees.depno = v.depno AND employees.sales >= v.target;
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103       Note that an AS clause is required when VALUES is used in a FROM
104       clause, just as is true for SELECT. It is not required that the AS
105       clause specify names for all the columns, but it's good practice to do
106       so. (The default column names for VALUES are column1, column2, etc in
107       PostgreSQL, but these names might be different in other database
108       systems.)
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110       When VALUES is used in INSERT, the values are all automatically coerced
111       to the data type of the corresponding destination column. When it's
112       used in other contexts, it might be necessary to specify the correct
113       data type. If the entries are all quoted literal constants, coercing
114       the first is sufficient to determine the assumed type for all:
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116           SELECT * FROM machines
117           WHERE ip_address IN (VALUES('192.168.0.1'::inet), ('192.168.0.10'), ('192.168.1.43'));
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119           Tip
120           For simple IN tests, it's better to rely on the list-of-scalars
121           form of IN than to write a VALUES query as shown above. The list of
122           scalars method requires less writing and is often more efficient.
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COMPATIBILITY

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