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Green_GoodERP18_FSJ_Standard/PostgreSQL/doc/postgresql/html/sql-values.html

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  1. <?xml version="1.0" encoding="UTF-8" standalone="no"?>

  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>VALUES</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="sql-vacuum.html" title="VACUUM" /><link rel="next" href="reference-client.html" title="PostgreSQL Client Applications" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">VALUES</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-vacuum.html" title="VACUUM">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 12.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="reference-client.html" title="PostgreSQL Client Applications">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="SQL-VALUES"><div class="titlepage"></div><a id="id-1.9.3.184.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">VALUES</span></h2><p>VALUES — compute a set of rows</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">

  3. VALUES ( <em class="replaceable"><code>expression</code></em> [, ...] ) [, ...]

  4.     [ ORDER BY <em class="replaceable"><code>sort_expression</code></em> [ ASC | DESC | USING <em class="replaceable"><code>operator</code></em> ] [, ...] ]

  5.     [ LIMIT { <em class="replaceable"><code>count</code></em> | ALL } ]

  6.     [ OFFSET <em class="replaceable"><code>start</code></em> [ ROW | ROWS ] ]

  7.     [ FETCH { FIRST | NEXT } [ <em class="replaceable"><code>count</code></em> ] { ROW | ROWS } ONLY ]

  8. </pre></div><div class="refsect1" id="id-1.9.3.184.5"><h2>Description</h2><p>

  9.    <code class="command">VALUES</code> computes a row value or set of row values

  10.    specified by value expressions.  It is most commonly used to generate

  11.    a <span class="quote">“<span class="quote">constant table</span>”</span> within a larger command, but it can be

  12.    used on its own.

  13.   </p><p>

  14.    When more than one row is specified, all the rows must have the same

  15.    number of elements.  The data types of the resulting table's columns are

  16.    determined by combining the explicit or inferred types of the expressions

  17.    appearing in that column, using the same rules as for <code class="literal">UNION</code>

  18.    (see <a class="xref" href="typeconv-union-case.html" title="10.5. UNION, CASE, and Related Constructs">Section 10.5</a>).

  19.   </p><p>

  20.    Within larger commands, <code class="command">VALUES</code> is syntactically allowed

  21.    anywhere that <code class="command">SELECT</code> is.  Because it is treated like a

  22.    <code class="command">SELECT</code> by the grammar, it is possible to use

  23.    the <code class="literal">ORDER BY</code>, <code class="literal">LIMIT</code> (or

  24.    equivalently <code class="literal">FETCH FIRST</code>),

  25.    and <code class="literal">OFFSET</code> clauses with a

  26.    <code class="command">VALUES</code> command.

  27.   </p></div><div class="refsect1" id="id-1.9.3.184.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>expression</code></em></span></dt><dd><p>

  28.       A constant or expression to compute and insert at the indicated place

  29.       in the resulting table (set of rows).  In a <code class="command">VALUES</code> list

  30.       appearing at the top level of an <code class="command">INSERT</code>, an

  31.       <em class="replaceable"><code>expression</code></em> can be replaced

  32.       by <code class="literal">DEFAULT</code> to indicate that the destination column's

  33.       default value should be inserted.  <code class="literal">DEFAULT</code> cannot

  34.       be used when <code class="command">VALUES</code> appears in other contexts.

  35.      </p></dd><dt><span class="term"><em class="replaceable"><code>sort_expression</code></em></span></dt><dd><p>

  36.       An expression or integer constant indicating how to sort the result

  37.       rows.  This expression can refer to the columns of the

  38.       <code class="command">VALUES</code> result as <code class="literal">column1</code>, <code class="literal">column2</code>,

  39.       etc.  For more details see

  40.       <a class="xref" href="sql-select.html#SQL-ORDERBY" title="ORDER BY Clause"><code class="literal">ORDER BY</code> Clause</a>.

  41.      </p></dd><dt><span class="term"><em class="replaceable"><code>operator</code></em></span></dt><dd><p>

  42.       A sorting operator.  For details see

  43.       <a class="xref" href="sql-select.html#SQL-ORDERBY" title="ORDER BY Clause"><code class="literal">ORDER BY</code> Clause</a>.

  44.      </p></dd><dt><span class="term"><em class="replaceable"><code>count</code></em></span></dt><dd><p>

  45.       The maximum number of rows to return.  For details see

  46.       <a class="xref" href="sql-select.html#SQL-LIMIT" title="LIMIT Clause"><code class="literal">LIMIT</code> Clause</a>.

  47.      </p></dd><dt><span class="term"><em class="replaceable"><code>start</code></em></span></dt><dd><p>

  48.       The number of rows to skip before starting to return rows.

  49.       For details see

  50.       <a class="xref" href="sql-select.html#SQL-LIMIT" title="LIMIT Clause"><code class="literal">LIMIT</code> Clause</a>.

  51.      </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.184.7"><h2>Notes</h2><p>

  52.    <code class="command">VALUES</code> lists with very large numbers of rows should be avoided,

  53.    as you might encounter out-of-memory failures or poor performance.

  54.    <code class="command">VALUES</code> appearing within <code class="command">INSERT</code> is a special case

  55.    (because the desired column types are known from the <code class="command">INSERT</code>'s

  56.    target table, and need not be inferred by scanning the <code class="command">VALUES</code>

  57.    list), so it can handle larger lists than are practical in other contexts.

  58.   </p></div><div class="refsect1" id="id-1.9.3.184.8"><h2>Examples</h2><p>

  59.    A bare <code class="command">VALUES</code> command:

  60. 

  61. </p><pre class="programlisting">

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

  63. </pre><p>

  64. 

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

  66.    equivalent to:

  67. 

  68. </p><pre class="programlisting">

  69. SELECT 1 AS column1, 'one' AS column2

  70. UNION ALL

  71. SELECT 2, 'two'

  72. UNION ALL

  73. SELECT 3, 'three';

  74. </pre><p>

  75. 

  76.   </p><p>

  77.    More usually, <code class="command">VALUES</code> is used within a larger SQL command.

  78.    The most common use is in <code class="command">INSERT</code>:

  79. 

  80. </p><pre class="programlisting">

  81. INSERT INTO films (code, title, did, date_prod, kind)

  82.     VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');

  83. </pre><p>

  84.   </p><p>

  85.    In the context of <code class="command">INSERT</code>, entries of a <code class="command">VALUES</code> list

  86.    can be <code class="literal">DEFAULT</code> to indicate that the column default

  87.    should be used here instead of specifying a value:

  88. 

  89. </p><pre class="programlisting">

  90. INSERT INTO films VALUES

  91.     ('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes'),

  92.     ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama', DEFAULT);

  93. </pre><p>

  94.   </p><p>

  95.    <code class="command">VALUES</code> can also be used where a sub-<code class="command">SELECT</code> might

  96.    be written, for example in a <code class="literal">FROM</code> clause:

  97. 

  98. </p><pre class="programlisting">

  99. SELECT f.*

  100.   FROM films f, (VALUES('MGM', 'Horror'), ('UA', 'Sci-Fi')) AS t (studio, kind)

  101.   WHERE f.studio = t.studio AND f.kind = t.kind;

  102. 

  103. UPDATE employees SET salary = salary * v.increase

  104.   FROM (VALUES(1, 200000, 1.2), (2, 400000, 1.4)) AS v (depno, target, increase)

  105.   WHERE employees.depno = v.depno AND employees.sales &gt;= v.target;

  106. </pre><p>

  107. 

  108.    Note that an <code class="literal">AS</code> clause is required when <code class="command">VALUES</code>

  109.    is used in a <code class="literal">FROM</code> clause, just as is true for

  110.    <code class="command">SELECT</code>.  It is not required that the <code class="literal">AS</code> clause

  111.    specify names for all the columns, but it's good practice to do so.

  112.    (The default column names for <code class="command">VALUES</code> are <code class="literal">column1</code>,

  113.    <code class="literal">column2</code>, etc in <span class="productname">PostgreSQL</span>, but

  114.    these names might be different in other database systems.)

  115.   </p><p>

  116.    When <code class="command">VALUES</code> is used in <code class="command">INSERT</code>, the values are all

  117.    automatically coerced to the data type of the corresponding destination

  118.    column.  When it's used in other contexts, it might be necessary to specify

  119.    the correct data type.  If the entries are all quoted literal constants,

  120.    coercing the first is sufficient to determine the assumed type for all:

  121. 

  122. </p><pre class="programlisting">

  123. SELECT * FROM machines

  124. WHERE ip_address IN (VALUES('192.168.0.1'::inet), ('192.168.0.10'), ('192.168.1.43'));

  125. </pre><div class="tip"><h3 class="title">Tip</h3><p>

  126.     For simple <code class="literal">IN</code> tests, it's better to rely on the

  127.     <a class="link" href="functions-comparisons.html#FUNCTIONS-COMPARISONS-IN-SCALAR" title="9.23.1. IN">list-of-scalars</a>

  128.     form of <code class="literal">IN</code> than to write a <code class="command">VALUES</code>

  129.     query as shown above.  The list of scalars method requires less writing

  130.     and is often more efficient.

  131.    </p></div></div><div class="refsect1" id="id-1.9.3.184.9"><h2>Compatibility</h2><p><code class="command">VALUES</code> conforms to the SQL standard.

  132.    <code class="literal">LIMIT</code> and <code class="literal">OFFSET</code> are

  133.    <span class="productname">PostgreSQL</span> extensions; see also

  134.    under <a class="xref" href="sql-select.html" title="SELECT"><span class="refentrytitle">SELECT</span></a>.

  135.   </p></div><div class="refsect1" id="id-1.9.3.184.10"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-insert.html" title="INSERT"><span class="refentrytitle">INSERT</span></a>, <a class="xref" href="sql-select.html" title="SELECT"><span class="refentrytitle">SELECT</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-vacuum.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="reference-client.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">VACUUM </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> PostgreSQL Client Applications</td></tr></table></div></body></html>
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