📄 function.mysql-unbuffered-query.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Send an SQL query to MySQL, without fetching and buffering the result rows</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.mysql.html">MySQL Functions</a></div> <div class="next" style="text-align: right; float: right;"><a href="book.mysqli.html">Mysqli</a></div> <div class="up"><a href="ref.mysql.html">MySQL Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.mysql-unbuffered-query" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysql_unbuffered_query</h1> <p class="verinfo">(PHP 4 >= 4.0.6, PHP 5, PECL mysql:1.0)</p><p class="refpurpose"><span class="refname">mysql_unbuffered_query</span> — <span class="dc-title">Send an SQL query to MySQL, without fetching and buffering the result rows</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">resource</span> <span class="methodname"><b><b>mysql_unbuffered_query</b></b></span> ( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$query</tt></span> [, <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$link_identifier</tt></span> ] )</div> <p class="para rdfs-comment"> <b>mysql_unbuffered_query()</b> sends a SQL query <i><tt class="parameter">query</tt></i> to MySQL, without fetching and buffering the result rows automatically, as <a href="function.mysql-query.html" class="function">mysql_query()</a> does. On the one hand, this saves a considerable amount of memory with SQL queries that produce large result sets. On the other hand, you can start working on the result set immediately after the first row has been retrieved: you don't have to wait until the complete SQL query has been performed. When using multiple DB-connects, you have to specify the optional parameter <i><tt class="parameter">link_identifier</tt></i>. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">query</tt></i></span> <dd> <p class="para"> A SQL query </p> </dd> </dt> <dt><span class="term"><i><tt class="parameter">link_identifier</tt></i></span><dd><p class="para">The MySQL connection. If the link identifier is not specified, the last link opened by <a href="function.mysql-connect.html" class="function">mysql_connect()</a> is assumed. If no such link is found, itwill try to create one as if <a href="function.mysql-connect.html" class="function">mysql_connect()</a> was calledwith no arguments. If by chance no connection is found or established, an<b><tt>E_WARNING</tt></b> level error is generated.</p></dd></dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> For SELECT, SHOW, DESCRIBE or EXPLAIN statements, <b>mysql_unbuffered_query()</b> returns a <a href="language.types.resource.html" class="type resource">resource</a> on success, or <b><tt>FALSE</tt></b> on error. </p> <p class="para"> For other type of SQL statements, UPDATE, DELETE, DROP, etc, <b>mysql_unbuffered_query()</b> returns <b><tt>TRUE</tt></b> on success or <b><tt>FALSE</tt></b> on error. </p> </div> <div class="refsect1 notes"> <h3 class="title">Notes</h3> <blockquote><p><b class="note">Note</b>: The benefits of <b>mysql_unbuffered_query()</b> come at a cost: You cannot use <a href="function.mysql-num-rows.html" class="function">mysql_num_rows()</a> and <a href="function.mysql-data-seek.html" class="function">mysql_data_seek()</a> on a result set returned from <b>mysql_unbuffered_query()</b>. You also have to fetch all result rows from an unbuffered SQL query, before you can send a new SQL query to MySQL. <br /> </p></blockquote> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.mysql-query.html" class="function" rel="rdfs-seeAlso">mysql_query()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.mysql.html">MySQL Functions</a></div> <div class="next" style="text-align: right; float: right;"><a href="book.mysqli.html">Mysqli</a></div> <div class="up"><a href="ref.mysql.html">MySQL Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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