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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"><html><head><title>SQLite Query Language: Aggregate Functions</title><style type="text/css">body {    margin: auto;    font-family: "Verdana" "sans-serif";    padding: 8px 1%;}a { color: #45735f }a:visited { color: #734559 }.logo { position:absolute; margin:3px; }.tagline {  float:right;  text-align:right;  font-style:italic;  width:240px;  margin:12px;  margin-top:58px;}.toolbar {  font-variant: small-caps;  text-align: center;  line-height: 1.6em;  margin: 0;  padding:1px 8px;}.toolbar a { color: white; text-decoration: none; padding: 6px 12px; }.toolbar a:visited { color: white; }.toolbar a:hover { color: #80a796; background: white; }.content    { margin: 5%; }.content dt { font-weight:bold; }.content dd { margin-bottom: 25px; margin-left:20%; }.content ul { padding:0px; padding-left: 15px; margin:0px; }/* rounded corners */.se  { background: url(images/se.png) 100% 100% no-repeat #80a796}.sw  { background: url(images/sw.png) 0% 100% no-repeat }.ne  { background: url(images/ne.png) 100% 0% no-repeat }.nw  { background: url(images/nw.png) 0% 0% no-repeat }</style><meta http-equiv="content-type" content="text/html; charset=UTF-8">  </head><body><div><!-- container div to satisfy validator --><a href="index.html"><img class="logo" src="images/SQLite.gif" alt="SQLite Logo" border="0"></a><div><!-- IE hack to prevent disappearing logo--></div><div class="tagline">Small. Fast. Reliable.<br>Choose any three.</div><table width=100% style="clear:both"><tr><td>  <div class="se"><div class="sw"><div class="ne"><div class="nw">  <div class="toolbar">    <a href="about.html">About</a>    <a href="sitemap.html">Sitemap</a>    <a href="docs.html">Documentation</a>    <a href="download.html">Download</a>    <a href="copyright.html">License</a>    <a href="news.html">News</a>    <a href="http://www.sqlite.org/cvstrac/index">Developers</a>    <a href="support.html">Support</a>  </div></div></div></div></div></td></tr></table>  <a href="lang.html"><h2>SQL As Understood By SQLite</h2></a><h3>Aggregate Functions</h3><p>The aggregate functions shown below are available by default.  Additionalaggregate functions written in C may be added using the <a href="c3ref/create_function.html">sqlite3_create_function()</a></a>API.</p><p>In any aggregate function that takes a single argument, that argumentcan be preceeded by the keyword DISTINCT.  In such cases, duplicateelements are filtered before being passed into the aggregate function.For example, the function "count(distinct X)" will return the numberof distinct values of column X instead of the total number of non-nullvalues in column X.</p><table border=0 cellpadding=10><tr><td valign="top" align="right" width="120">avg(<i>X</i>)</td><td valign="top"><a name="avg"></a>  Return the average value of all non-NULL <i>X</i> within a  group.  String and BLOB values that do not look like numbers are  interpreted as 0.  The result of avg() is always a floating point value even if all  inputs are integers.</td></tr><tr><td valign="top" align="right" width="120">count(<i>X</i>)<br></br>count(*)</td><td valign="top"><a name="count"></a>  The first form return a count of the number of times  that <i>X</i> is not NULL in a group.  The second form (with no argument)  returns the total number of rows in the group.</td></tr><tr><td valign="top" align="right" width="120">group_concat(<i>X</i>)<br></br>group_concat(<i>X</i>,<i>Y</i>)</td><td valign="top"><a name="group_concat"></a>  The result is a string which is the concatenation of  all non-NULL values of <i>X</i>.  If parameter <i>Y</i> is the separator  between instances of <i>X</i>.  A comma (",") is used as the separator  if <i>Y</i> is omitted.</td></tr><tr><td valign="top" align="right" width="120">max(<i>X</i>)</td><td valign="top"><a name="maxAggFunc"></a>  Return the maximum value of all values in the group.  The usual sort order is used to determine the maximum.</td></tr><tr><td valign="top" align="right" width="120">min(<i>X</i>)</td><td valign="top"><a name="minAggFunc"></a>  Return the minimum non-NULL value of all values in the group.  The usual sort order is used to determine the minimum.    NULL is only returned  if all values in the group are NULL.</td></tr><tr><td valign="top" align="right" width="120">sum(<i>X</i>)<br></br>total(<i>X</i>)</td><td valign="top"><a name="sumFunc"></a>  Return the numeric sum of all non-NULL values in the group.  If there are no non-NULL input rows then sum() returns  NULL but total() returns 0.0.  NULL is not normally a helpful result for the sum of no rows  but the SQL standard requires it and most other  SQL database engines implement sum() that way so SQLite does it in the  same way in order to be compatible.   The non-standard total() function  is provided as a convenient way to work around this design problem  in the SQL language.</p>  <p>The result of total() is always a floating point value.  The result of sum() is an integer value if all non-NULL inputs are integers.  If any input to sum() is neither an integer or a NULL  then sum() returns a floating point value  which might be an approximation to the true sum.</p>  <p>Sum() will throw an "integer overflow" exception if all inputs  are integers or NULL  and an integer overflow occurs at any point during the computation.  Total() never throws an exception.</td></tr></table><hr><small><i>This page last modified 2008/04/27 17:48:52 UTC</i></small></div></body></html>
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