📄 function.mysql-field-len.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>Returns the length of the specified field</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="function.mysql-field-flags.html">mysql_field_flags</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.mysql-field-name.html">mysql_field_name</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-field-len" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysql_field_len</h1> <p class="verinfo">(PHP 4, PHP 5, PECL mysql:1.0)</p><p class="refpurpose"><span class="refname">mysql_field_len</span> — <span class="dc-title">Returns the length of the specified field</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">int</span> <span class="methodname"><b><b>mysql_field_len</b></b></span> ( <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$result</tt></span> , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$field_offset</tt></span> )</div> <p class="para rdfs-comment"> <b>mysql_field_len()</b> returns the length of the specified field. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt><span class="term"><i><tt class="parameter">result</tt></i></span><dd><p class="para">The result <a href="language.types.resource.html" class="type resource">resource</a> thatis being evaluated. This result comes from a call to <a href="function.mysql-query.html" class="function">mysql_query()</a>.</p></dd></dt> <dt><span class="term"><i><tt class="parameter">field_offset</tt></i></span><dd><p class="para">The numerical field offset. The <i><tt class="parameter">field_offset</tt></i> starts at <i>0</i>. If <i><tt class="parameter">field_offset</tt></i> does not exist, an error of level<b><tt>E_WARNING</tt></b> is also issued.</p></dd></dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The length of the specified field index on success, or <b><tt>FALSE</tt></b> on failure. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>mysql_field_len()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysql_query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT id,email FROM people WHERE id = '42'"</span><span style="color: #007700">);<br />if (!</span><span style="color: #0000BB">$result</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">'Could not run query: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">mysql_error</span><span style="color: #007700">();<br /> exit;<br />}<br /><br /></span><span style="color: #FF8000">// Will get the length of the id field as specified in the database<br />// schema. <br /></span><span style="color: #0000BB">$length </span><span style="color: #007700">= </span><span style="color: #0000BB">mysql_field_len</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$length</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 notes"> <h3 class="title">Notes</h3> <blockquote><p><b class="note">Note</b>: For backward compatibility, the following deprecated alias may be used: <b>mysql_fieldlen()</b> <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-fetch-lengths.html" class="function" rel="rdfs-seeAlso">mysql_fetch_lengths()</a></li> <li class="member"><a href="function.strlen.html" class="function" rel="rdfs-seeAlso">strlen()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.mysql-field-flags.html">mysql_field_flags</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.mysql-field-name.html">mysql_field_name</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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