mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-18 05:26:57 +08:00
95 lines
3.5 KiB
HTML
95 lines
3.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
|
|
<title>Returns the number of rows affected by an SQL statement</title>
|
|
</head>
|
|
<body class="docs"><div id="layout">
|
|
<div id="layout-content"><div id="function.db2-num-rows" class="refentry">
|
|
<div class="refnamediv">
|
|
<h1 class="refname">db2_num_rows</h1>
|
|
<p class="verinfo">(PECL ibm_db2 >= 1.0.0)</p><p class="refpurpose"><span class="refname">db2_num_rows</span> — <span class="dc-title">
|
|
Returns the number of rows affected by an SQL statement
|
|
</span></p>
|
|
|
|
</div>
|
|
<div class="refsect1 description" id="refsect1-function.db2-num-rows-description">
|
|
<h3 class="title">说明</h3>
|
|
<div class="methodsynopsis dc-description">
|
|
<span class="methodname"><strong>db2_num_rows</strong></span>
|
|
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$stmt</code></span>
|
|
) : <span class="type">int</span></div>
|
|
|
|
|
|
|
|
<p class="para rdfs-comment">
|
|
Returns the number of rows deleted, inserted, or updated by an SQL
|
|
statement.
|
|
</p>
|
|
<p class="para">
|
|
To determine the number of rows that will be returned by a SELECT
|
|
statement, issue SELECT COUNT(*) with the same predicates as your
|
|
intended SELECT statement and retrieve the value.
|
|
</p>
|
|
<p class="para">
|
|
If your application logic checks the number of rows returned by a SELECT
|
|
statement and branches if the number of rows is 0, consider modifying your
|
|
application to attempt to return the first row with one of
|
|
<span class="function"><a href="db2_fetch_assoc.html" class="function">db2_fetch_assoc()</a></span>, <span class="function"><a href="db2_fetch_both.html" class="function">db2_fetch_both()</a></span>,
|
|
<span class="function"><a href="db2_fetch_array.html" class="function">db2_fetch_array()</a></span>, or <span class="function"><a href="db2_fetch_row.html" class="function">db2_fetch_row()</a></span>,
|
|
and branch if the fetch function returns <strong><code>FALSE</code></strong>.
|
|
</p>
|
|
|
|
<blockquote class="note"><p><strong class="note">Note</strong>:
|
|
<p class="para">
|
|
If you issue a SELECT statement using a scrollable cursor,
|
|
<span class="function"><strong>db2_num_rows()</strong></span> returns the number of rows returned by
|
|
the SELECT statement. However, the overhead associated with scrollable
|
|
cursors significantly degrades the performance of your application, so if
|
|
this is the only reason you are considering using scrollable cursors,
|
|
you should use a forward-only cursor and either call SELECT COUNT(*) or
|
|
rely on the <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span> return value of the fetch functions to
|
|
achieve the equivalent functionality with much better performance.
|
|
</p>
|
|
</p></blockquote>
|
|
|
|
</div>
|
|
|
|
<div class="refsect1 parameters" id="refsect1-function.db2-num-rows-parameters">
|
|
<h3 class="title">参数</h3>
|
|
<p class="para">
|
|
<dl>
|
|
|
|
|
|
<dt>
|
|
<code class="parameter">stmt</code></dt>
|
|
|
|
<dd>
|
|
|
|
<p class="para">
|
|
A valid <em>stmt</em> resource containing a result set.
|
|
</p>
|
|
</dd>
|
|
|
|
|
|
</dl>
|
|
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsect1 returnvalues" id="refsect1-function.db2-num-rows-returnvalues">
|
|
<h3 class="title">返回值</h3>
|
|
<p class="para">
|
|
Returns the number of rows affected by the last SQL statement issued by
|
|
the specified statement handle.
|
|
</p>
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</div></div></div></body></html> |