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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>Returns result set metadata from a prepared statement</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-stmt.reset.html">mysqli_stmt::reset</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli-stmt.send-long-data.html">mysqli_stmt::send_long_data</a></div> <div class="up"><a href="class.mysqli-stmt.html">MySQLi_STMT</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="mysqli-stmt.result-metadata" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysqli_stmt::result_metadata</h1> <h1 class="refname">mysqli_stmt_result_metadata</h1> <p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">mysqli_stmt::result_metadata</span> -- <span class="refname">mysqli_stmt_result_metadata</span> — <span class="dc-title">Returns result set metadata from a prepared statement</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>mysqli_stmt::result_metadata</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_stmt_result_metadata</b></b></span> ( <span class="methodparam"><span class="type"><span class="type mysqli_stmt">mysqli_stmt</span></span> <tt class="parameter">$stmt</tt></span> )</div> <p class="para rdfs-comment"> If a statement passed to <a href="mysqli.prepare.html" class="function">mysqli_prepare()</a> is one that produces a result set, <b>mysqli_stmt_result_metadata()</b> returns the result object that can be used to process the meta information such as total number of fields and individual field information. </p> <blockquote><p><b class="note">Note</b>: This result set pointer can be passed as an argument to any of the field-based functions that process result set metadata, such as: <ul class="itemizedlist"> <li class="listitem"><p class="para"><a href="mysqli-result.field-count.html" class="function">mysqli_num_fields()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.fetch-field.html" class="function">mysqli_fetch_field()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.fetch-field-direct.html" class="function">mysqli_fetch_field_direct()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.fetch-fields.html" class="function">mysqli_fetch_fields()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli.field-count.html" class="function">mysqli_field_count()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.field-seek.html" class="function">mysqli_field_seek()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.current-field.html" class="function">mysqli_field_tell()</a></p></li> <li class="listitem"><p class="para"><a href="mysqli-result.free.html" class="function">mysqli_free_result()</a></p></li> </ul> <br /> </p></blockquote> <p class="para"> The result set structure should be freed when you are done with it, which you can do by passing it to <a href="mysqli-result.free.html" class="function">mysqli_free_result()</a> </p> <blockquote><p><b class="note">Note</b>: The result set returned by <b>mysqli_stmt_result_metadata()</b> contains only metadata. It does not contain any row results. The rows are obtained by using the statement handle with <a href="mysqli-stmt.fetch.html" class="function">mysqli_stmt_fetch()</a>. <br /> </p></blockquote> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt><span class="term"><i><tt class="parameter">stmt</tt></i></span><dd><p class="para">Procedural style only: A statement identifierreturned by <a href="mysqli.stmt-init.html" class="function">mysqli_stmt_init()</a>.</p></dd></dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns a result object or <b><tt>FALSE</tt></b> if an error occured. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <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">"test"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"DROP TABLE IF EXISTS friends"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"CREATE TABLE friends (id int, name varchar(20))"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$stmt </span><span style="color: #007700">= </span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT id, name FROM friends"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* get resultset for metadata */<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">result_metadata</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* retrieve field information from metadata result set */<br /></span><span style="color: #0000BB">$field </span><span style="color: #007700">= </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch_field</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Fieldname: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$field</span><span style="color: #007700">-></span><span style="color: #0000BB">name</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* close resultset */<br /></span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* 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">"test"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"DROP TABLE IF EXISTS friends"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"CREATE TABLE friends (id int, name varchar(20))"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$stmt </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_prepare</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"SELECT id, name FROM friends"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">mysqli_stmt_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* get resultset for metadata */<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_stmt_result_metadata</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* retrieve field information from metadata result set */<br /></span><span style="color: #0000BB">$field </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_fetch_field</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Fieldname: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$field</span><span style="color: #007700">-></span><span style="color: #0000BB">name</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* close resultset */<br /></span><span style="color: #0000BB">mysqli_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* 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> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="mysqli.prepare.html" class="function" rel="rdfs-seeAlso">mysqli_prepare()</a></li> <li class="member"><a href="mysqli-result.free.html" class="function" rel="rdfs-seeAlso">mysqli_free_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-stmt.reset.html">mysqli_stmt::reset</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli-stmt.send-long-data.html">mysqli_stmt::send_long_data</a></div> <div class="up"><a href="class.mysqli-stmt.html">MySQLi_STMT</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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