mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-18 05:26:57 +08:00
45 lines
5.0 KiB
HTML
45 lines
5.0 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>测试字段是否为 NULL</title>
|
||
</head>
|
||
<body class="docs"><div id="layout">
|
||
<div id="layout-content"><div id="function.pg-field-is-null" class="refentry">
|
||
<div class="refnamediv">
|
||
<h1 class="refname">pg_field_is_null</h1>
|
||
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">pg_field_is_null</span> — <span class="dc-title">测试字段是否为 <strong><code>NULL</code></strong></span></p>
|
||
|
||
</div>
|
||
<div class="refsect1 unknown-seealsp" id="refsect1-function.pg-field-is-null-unknown-seealsp">
|
||
<h3 class="title">说明</h3>
|
||
<div class="methodsynopsis dc-description">
|
||
<span class="methodname"><strong>pg_field_is_null</strong></span>
|
||
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$result</code></span>
|
||
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$row</code></span>
|
||
, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$field</code></span>
|
||
) : <span class="type">int</span></div>
|
||
|
||
<p class="para rdfs-comment">
|
||
<span class="function"><strong>pg_field_is_null()</strong></span> 测试字段是否为 <strong><code>NULL</code></strong>。如果字段在给出的行中为 <strong><code>NULL</code></strong> 则返回 1，如果字段在给出的行中不是 <strong><code>NULL</code></strong> 则返回 0。字段可以以列的索引号（数字）方式给出，也可以以字段名（字符串）方式给出。行的编号从 0 开始。
|
||
</p>
|
||
<p class="para">
|
||
<div class="example" id="example-2493">
|
||
<p><strong>Example #1 <span class="function"><strong>pg_field_is_null()</strong></span> 例子</strong></p>
|
||
<div class="example-contents">
|
||
<div class="phpcode"><pre><span style="color: #000000">
|
||
<span style="color: #0000BB"><?php<br /> $dbconn </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=publisher"</span><span style="color: #007700">) or die (</span><span style="color: #DD0000">"Could not connect"</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$res </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">, </span><span style="color: #DD0000">"select * from authors where author = 'Orwell'"</span><span style="color: #007700">);<br /> if (</span><span style="color: #0000BB">$res</span><span style="color: #007700">) {<br /> if (</span><span style="color: #0000BB">pg_field_is_null</span><span style="color: #007700">(</span><span style="color: #0000BB">$res</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #DD0000">"year"</span><span style="color: #007700">) == </span><span style="color: #0000BB">1</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"The value of the field year is null.\n"</span><span style="color: #007700">;<br /> }<br /> if (</span><span style="color: #0000BB">pg_field_is_null</span><span style="color: #007700">(</span><span style="color: #0000BB">$res</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #DD0000">"year"</span><span style="color: #007700">) == </span><span style="color: #0000BB">0</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"The value of the field year is not null.\n"</span><span style="color: #007700">;<br /> }<br /> }<br /></span><span style="color: #0000BB">?></span>
|
||
</span>
|
||
</pre></div>
|
||
</div>
|
||
|
||
</div>
|
||
</p>
|
||
<blockquote class="note"><p><strong class="note">Note</strong>:
|
||
<p class="para">
|
||
本函数以前的名字为 <em>pg_fieldisnull()</em>。
|
||
</p>
|
||
</p></blockquote>
|
||
</div>
|
||
|
||
</div></div></div></body></html> |