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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 lengths of the columns of the current row in the result set</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-result.free.html">mysqli_result::free</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli-result.num-rows.html">mysqli_result->num_rows</a></div> <div class="up"><a href="class.mysqli-result.html">MySQLi_Result</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="mysqli-result.lengths" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysqli_result->lengths</h1> <h1 class="refname">mysqli_fetch_lengths</h1> <p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">mysqli_result->lengths</span> -- <span class="refname">mysqli_fetch_lengths</span> — <span class="dc-title">Returns the lengths of the columns of the current row in the result set</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <p class="para">Object oriented style (property):</p> <div class="classsynopsis"> <div class="ooclass"><a href="class.mysqli-result.html" class="classname">mysqli_result</a></div> <div class="fieldsynopsis"><span class="type">array</span> <var class="varname">$lengths</var>;</div> </div> <p class="para">Procedural style:</p> <div class="methodsynopsis dc-description"> <span class="type">array</span> <span class="methodname"><b><b>mysqli_fetch_lengths</b></b></span> ( <span class="methodparam"><span class="type"><span class="type mysqli_result">mysqli_result</span></span> <tt class="parameter">$result</tt></span> )</div> <p class="para rdfs-comment"> The <b>mysqli_fetch_lengths()</b> function returns an array containing the lengths of every column of the current row within the result set. </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">Procedural style only: A result setidentifier returned by <a href="mysqli.query.html" class="function">mysqli_query()</a>, <a href="mysqli.store-result.html" class="function">mysqli_store_result()</a>or <a href="mysqli.use-result.html" class="function">mysqli_use_result()</a>.</p></dd></dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> An array of integers representing the size of each column (not including any terminating null characters). <b><tt>FALSE</tt></b> if an error occurred. </p> <p class="para"> <b>mysqli_fetch_lengths()</b> is valid only for the current row of the result set. It returns <b><tt>FALSE</tt></b> if you call it before calling mysqli_fetch_row/array/object or after retrieving all rows in the result. </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 * from Country ORDER BY Code LIMIT 1"</span><span style="color: #007700">;<br /><br />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">query</span><span style="color: #007700">(</span><span style="color: #0000BB">$query</span><span style="color: #007700">)) {<br /><br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch_row</span><span style="color: #007700">();<br /><br /> </span><span style="color: #FF8000">/* display column lengths */<br /> </span><span style="color: #007700">foreach (</span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">lengths </span><span style="color: #007700">as </span><span style="color: #0000BB">$i </span><span style="color: #007700">=> </span><span style="color: #0000BB">$val</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Field %2d has Length %2d\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$i</span><span style="color: #007700">+</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">$val</span><span style="color: #007700">);<br /> }<br /> </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">$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 * from Country ORDER BY Code LIMIT 1"</span><span style="color: #007700">;<br /><br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #0000BB">$query</span><span style="color: #007700">)) {<br /><br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_fetch_row</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br /> </span><span style="color: #FF8000">/* display column lengths */<br /> </span><span style="color: #007700">foreach (</span><span style="color: #0000BB">mysqli_fetch_lengths</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">) as </span><span style="color: #0000BB">$i </span><span style="color: #007700">=> </span><span style="color: #0000BB">$val</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Field %2d has Length %2d\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$i</span><span style="color: #007700">+</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">$val</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">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">mysqli_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$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>Field 1 has Length 3Field 2 has Length 5Field 3 has Length 13Field 4 has Length 9Field 5 has Length 6Field 6 has Length 1Field 7 has Length 6Field 8 has Length 4Field 9 has Length 6Field 10 has Length 6Field 11 has Length 5Field 12 has Length 44Field 13 has Length 7Field 14 has Length 3Field 15 has Length 2</pre></div> </pre></div> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="mysqli-result.free.html">mysqli_result::free</a></div> <div class="next" style="text-align: right; float: right;"><a href="mysqli-result.num-rows.html">mysqli_result->num_rows</a></div> <div class="up"><a href="class.mysqli-result.html">MySQLi_Result</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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