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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>Initiate a result set retrieval</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="mysqli.thread-safe.html">mysqli::thread_safe</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli.warning-count.html">mysqli::warning_count</a></div> <div class="up"><a href="class.mysqli.html">MySQLi</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="mysqli.use-result" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysqli::use_result</h1> <h1 class="refname">mysqli_use_result</h1> <p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">mysqli::use_result</span> -- <span class="refname">mysqli_use_result</span> — <span class="dc-title">Initiate a result set retrieval</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <p class="para">Object oriented style (method):</p> <div class="methodsynopsis dc-description"> <span class="type"><span class="type mysqli_result">mysqli_result</span></span> <span class="methodname"><b><b>use_result</b></b></span> ( <span class="methodparam">void</span> )</div> <p class="para rdfs-comment">Procedural style:</p> <div class="methodsynopsis dc-description"> <span class="type"><span class="type mysqli_result">mysqli_result</span></span> <span class="methodname"><b><b>mysqli_use_result</b></b></span> ( <span class="methodparam"><span class="type"><a href="class.mysqli.html" class="type mysqli">mysqli</a></span> <tt class="parameter">$link</tt></span> )</div> <p class="para rdfs-comment"> Used to initiate the retrieval of a result set from the last query executed using the <a href="mysqli.real-query.html" class="function">mysqli_real_query()</a> function on the database connection. </p> <p class="para"> Either this or the <a href="mysqli.store-result.html" class="function">mysqli_store_result()</a> function must be called before the results of a query can be retrieved, and one or the other must be called to prevent the next query on that database connection from failing. </p> <blockquote><p><b class="note">Note</b>: The <b>mysqli_use_result()</b> function does not transfer the entire result set from the database and hence cannot be used functions such as <a href="mysqli-result.data-seek.html" class="function">mysqli_data_seek()</a> to move to a particular row within the set. To use this functionality, the result set must be stored using <a href="mysqli.store-result.html" class="function">mysqli_store_result()</a>. One should not use <b>mysqli_use_result()</b> if a lot of processing on the client side is performed, since this will tie up the server and prevent other threads from updating any tables from which the data is being fetched. <br /> </p></blockquote> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns an unbuffered result object or <b><tt>FALSE</tt></b> if an error occurred. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <div class="example"> <p><b>Example #1 Object oriented style</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$mysqli </span><span style="color: #007700">= new </span><span style="color: #0000BB">mysqli</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* check connection */<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">mysqli_connect_errno</span><span style="color: #007700">()) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect failed: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br /> exit();<br />}<br /><br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">= </span><span style="color: #DD0000">"SELECT CURRENT_USER();"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">.= </span><span style="color: #DD0000">"SELECT Name FROM City ORDER BY ID LIMIT 20, 5"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">/* execute multi query */<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">multi_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$query</span><span style="color: #007700">)) {<br /> do {<br /> </span><span style="color: #FF8000">/* store first result set */<br /> </span><span style="color: #007700">if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">use_result</span><span style="color: #007700">()) {<br /> while (</span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch_row</span><span style="color: #007700">()) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"%s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]);<br /> }<br /> </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /> }<br /> </span><span style="color: #FF8000">/* print divider */<br /> </span><span style="color: #007700">if (</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">more_results</span><span style="color: #007700">()) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"-----------------\n"</span><span style="color: #007700">);<br /> }<br /> } while (</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">next_result</span><span style="color: #007700">());<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> <div class="example"> <p><b>Example #2 Procedural style</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$link </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* check connection */<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">mysqli_connect_errno</span><span style="color: #007700">()) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect failed: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br /> exit();<br />}<br /><br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">= </span><span style="color: #DD0000">"SELECT CURRENT_USER();"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">.= </span><span style="color: #DD0000">"SELECT Name FROM City ORDER BY ID LIMIT 20, 5"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">/* execute multi query */<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">mysqli_multi_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #0000BB">$query</span><span style="color: #007700">)) {<br /> do {<br /> </span><span style="color: #FF8000">/* store first result set */<br /> </span><span style="color: #007700">if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_use_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">)) {<br /> while (</span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_fetch_row</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"%s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]);<br /> }<br /> </span><span style="color: #0000BB">mysqli_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /> }<br /> </span><span style="color: #FF8000">/* print divider */<br /> </span><span style="color: #007700">if (</span><span style="color: #0000BB">mysqli_more_results</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"-----------------\n"</span><span style="color: #007700">);<br /> }<br /> } while (</span><span style="color: #0000BB">mysqli_next_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">));<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">mysqli_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> <p class="para">The above example will output:</p> <div class="example-contents"><pre><div class="cdata"><pre>my_user@localhost-----------------AmersfoortMaastrichtDordrechtLeidenHaarlemmermeer</pre></div> </pre></div> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="mysqli.real-query.html" class="function" rel="rdfs-seeAlso">mysqli_real_query()</a></li> <li class="member"><a href="mysqli.store-result.html" class="function" rel="rdfs-seeAlso">mysqli_store_result()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="mysqli.thread-safe.html">mysqli::thread_safe</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli.warning-count.html">mysqli::warning_count</a></div> <div class="up"><a href="class.mysqli.html">MySQLi</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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