function.dbx-compare.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>Compare two rows for sorting purposes</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.dbx-close.html">dbx_close</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.dbx-connect.html">dbx_connect</a></div> <div class="up"><a href="ref.dbx.html">dbx Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.dbx-compare" class="refentry"> <div class="refnamediv"> <h1 class="refname">dbx_compare</h1> <p class="verinfo">(PHP 4 >= 4.0.7, PHP 5 <= 5.0.5, PECL dbx:1.1.0)</p><p class="refpurpose"><span class="refname">dbx_compare</span> — <span class="dc-title">Compare two rows for sorting purposes</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>dbx_compare</b></b></span> ( <span class="methodparam"><span class="type">array</span> <tt class="parameter">$row_a</tt></span> , <span class="methodparam"><span class="type">array</span> <tt class="parameter">$row_b</tt></span> , <span class="methodparam"><span class="type">string</span> <tt class="parameter">$column_key</tt></span> [, <span class="methodparam"><span class="type">int</span> <tt class="parameter">$flags</tt></span> ] )</div> <p class="para rdfs-comment"> <b>dbx_compare()</b> is a helper function for <a href="function.dbx-sort.html" class="function">dbx_sort()</a> to ease the make and use of the custom sorting function. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">row_a</tt></i></span> <dd> <p class="para"> First row </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">row_b</tt></i></span> <dd> <p class="para"> Second row </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">column_key</tt></i></span> <dd> <p class="para"> The compared column </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">flags</tt></i></span> <dd> <p class="para"> The <i><tt class="parameter">flags</tt></i> can be set to specify comparison direction: <ul class="itemizedlist"> <li class="listitem"> <span class="simpara"> <b><tt>DBX_CMP_ASC</tt></b> - ascending order </span> </li> <li class="listitem"> <span class="simpara"> <b><tt>DBX_CMP_DESC</tt></b> - descending order </span> </li> </ul> and the preferred comparison type: <ul class="itemizedlist"> <li class="listitem"> <span class="simpara"> <b><tt>DBX_CMP_NATIVE</tt></b> - no type conversion </span> </li> <li class="listitem"> <span class="simpara"> <b><tt>DBX_CMP_TEXT</tt></b> - compare items as strings </span> </li> <li class="listitem"> <span class="simpara"> <b><tt>DBX_CMP_NUMBER</tt></b> - compare items numerically </span> </li> </ul> One of the direction and one of the type constant can be combined with bitwise OR operator (|). The default value for the <i><tt class="parameter">flags</tt></i> parameter is <b><tt>DBX_CMP_ASC</tt></b> | <b><tt>DBX_CMP_NATIVE</tt></b>. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <i>0</i> if the <i>row_a[$column_key]</i> is equal to <i>row_b[$column_key]</i>, and <i>1</i> or <i>-1</i> if the former is greater or is smaller than the latter one, respectively, or vice versa if the <i><tt class="parameter">flag</tt></i> is set to <b><tt>DBX_CMP_DESC</tt></b>. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>dbx_compare()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #007700">function </span><span style="color: #0000BB">user_re_order</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">) <br />{<br /> </span><span style="color: #0000BB">$rv </span><span style="color: #007700">= </span><span style="color: #0000BB">dbx_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">, </span><span style="color: #DD0000">"parentid"</span><span style="color: #007700">, </span><span style="color: #0000BB">DBX_CMP_DESC</span><span style="color: #007700">);<br /> if (!</span><span style="color: #0000BB">$rv</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">$rv </span><span style="color: #007700">= </span><span style="color: #0000BB">dbx_compare</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">, </span><span style="color: #DD0000">"id"</span><span style="color: #007700">, </span><span style="color: #0000BB">DBX_CMP_NUMBER</span><span style="color: #007700">);<br /> }<br /> return </span><span style="color: #0000BB">$rv</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">$link </span><span style="color: #007700">= </span><span style="color: #0000BB">dbx_connect</span><span style="color: #007700">(</span><span style="color: #0000BB">DBX_ODBC</span><span style="color: #007700">, </span><span style="color: #DD0000">""</span><span style="color: #007700">, </span><span style="color: #DD0000">"db"</span><span style="color: #007700">, </span><span style="color: #DD0000">"username"</span><span style="color: #007700">, </span><span style="color: #DD0000">"password"</span><span style="color: #007700">)<br /> or die(</span><span style="color: #DD0000">"Could not connect"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">dbx_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"SELECT id, parentid, description FROM table ORDER BY id"</span><span style="color: #007700">);<br /> </span><span style="color: #FF8000">// data in $result is now ordered by id<br /><br /></span><span style="color: #0000BB">dbx_sort</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">, </span><span style="color: #DD0000">"user_re_order"</span><span style="color: #007700">);<br /> </span><span style="color: #FF8000">// date in $result is now ordered by parentid (descending), then by id<br /><br /></span><span style="color: #0000BB">dbx_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$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="function.dbx-sort.html" class="function" rel="rdfs-seeAlso">dbx_sort()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.dbx-close.html">dbx_close</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.dbx-connect.html">dbx_connect</a></div> <div class="up"><a href="ref.dbx.html">dbx 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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