uTools-Manuals/docs/php/pg_prepare.html
2019-04-08 23:22:26 +08:00

142 lines
8.2 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>Submits a request to create a prepared statement with the
given parameters, and waits for completion</title>
</head>
<body class="docs"></div>
<div id="layout">
<div id="layout-content"><div id="function.pg-prepare" class="refentry">
<div class="refnamediv">
<h1 class="refname">pg_prepare</h1>
<p class="verinfo">(PHP 5 &gt;= 5.1.0, PHP 7)</p><p class="refpurpose"><span class="refname">pg_prepare</span> &mdash; <span class="dc-title"> Submits a request to create a prepared statement with the
given parameters, and waits for completion</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.pg-prepare-description">
<h3 class="title">说明</h3>
<div class="methodsynopsis dc-description">
<span class="methodname"><strong>pg_prepare</strong></span>
([ <span class="methodparam"><span class="type">resource</span> <code class="parameter">$connection</code></span>
], <span class="methodparam"><span class="type">string</span> <code class="parameter">$stmtname</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>
) : <span class="type">resource</span></div>
<p class="para rdfs-comment">
<span class="function"><strong>pg_prepare()</strong></span> creates a prepared statement for later execution with
<span class="function"><a href="pg_execute.html" class="function">pg_execute()</a></span> or <span class="function"><a href="pg_send_execute.html" class="function">pg_send_execute()</a></span>.
This feature allows commands that will be used repeatedly to
be parsed and planned just once, rather than each time they are executed.
<span class="function"><strong>pg_prepare()</strong></span> is supported only against PostgreSQL 7.4 or
higher connections; it will fail when using earlier versions.
</p>
<p class="para">
The function creates a prepared statement named <code class="parameter">stmtname</code> from the <code class="parameter">query</code>
string, which must contain a single SQL command. <code class="parameter">stmtname</code> may be &quot;&quot; to
create an unnamed statement, in which case any pre-existing unnamed
statement is automatically replaced; otherwise it is an error if the
statement name is already defined in the current session. If any parameters
are used, they are referred to in the <code class="parameter">query</code> as $1, $2, etc.
</p>
<p class="para">
Prepared statements for use with <span class="function"><strong>pg_prepare()</strong></span> can also be created by
executing SQL <em>PREPARE</em> statements. (But <span class="function"><strong>pg_prepare()</strong></span> is more flexible since it
does not require parameter types to be pre-specified.) Also, although there
is no PHP function for deleting a prepared statement, the SQL <em>DEALLOCATE</em>
statement can be used for that purpose.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.pg-prepare-parameters">
<h3 class="title">参数</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">connection</code></dt>
<dd>
<p class="para">
PostgreSQL database connection resource. When
<code class="parameter">connection</code> is not present, the default connection
is used. The default connection is the last connection made by
<span class="function"><a href="pg_connect.html" class="function">pg_connect()</a></span> or <span class="function"><a href="pg_pconnect.html" class="function">pg_pconnect()</a></span>.
</p>
</dd>
<dt>
<code class="parameter">stmtname</code></dt>
<dd>
<p class="para">
The name to give the prepared statement. Must be unique per-connection. If
&quot;&quot; is specified, then an unnamed statement is created, overwriting any
previously defined unnamed statement.
</p>
</dd>
<dt>
<code class="parameter">query</code></dt>
<dd>
<p class="para">
The parameterized SQL statement. Must contain only a single statement.
(multiple statements separated by semi-colons are not allowed.) If any parameters
are used, they are referred to as $1, $2, etc.
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.pg-prepare-returnvalues">
<h3 class="title">返回值</h3>
<p class="para">
A query result resource on success 或者在失败时返回 <strong><code>FALSE</code></strong>.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.pg-prepare-examples">
<h3 class="title">范例</h3>
<p class="para">
<div class="example" id="example-2510">
<p><strong>Example #1 Using <span class="function"><strong>pg_prepare()</strong></span></strong></p>
<div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;Connect&nbsp;to&nbsp;a&nbsp;database&nbsp;named&nbsp;"mary"<br /></span><span style="color: #0000BB">$dbconn&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=mary"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;Prepare&nbsp;a&nbsp;query&nbsp;for&nbsp;execution<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_prepare</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'SELECT&nbsp;*&nbsp;FROM&nbsp;shops&nbsp;WHERE&nbsp;name&nbsp;=&nbsp;$1'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;Execute&nbsp;the&nbsp;prepared&nbsp;query.&nbsp;&nbsp;Note&nbsp;that&nbsp;it&nbsp;is&nbsp;not&nbsp;necessary&nbsp;to&nbsp;escape<br />//&nbsp;the&nbsp;string&nbsp;"Joe's&nbsp;Widgets"&nbsp;in&nbsp;any&nbsp;way<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;array(</span><span style="color: #DD0000">"Joe's&nbsp;Widgets"</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">//&nbsp;Execute&nbsp;the&nbsp;same&nbsp;prepared&nbsp;query,&nbsp;this&nbsp;time&nbsp;with&nbsp;a&nbsp;different&nbsp;parameter<br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_query"</span><span style="color: #007700">,&nbsp;array(</span><span style="color: #DD0000">"Clothes&nbsp;Clothes&nbsp;Clothes"</span><span style="color: #007700">));<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.pg-prepare-seealso">
<h3 class="title">参见</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="pg_execute.html" class="function" rel="rdfs-seeAlso">pg_execute()</a> - Sends a request to execute a prepared statement with given parameters, and waits for the result</span></li>
<li class="member"><span class="function"><a href="pg_send_execute.html" class="function" rel="rdfs-seeAlso">pg_send_execute()</a> - Sends a request to execute a prepared statement with given parameters, without waiting for the result(s)</span></li>
</ul>
</p>
</div>
</div></div></div></body></html>