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<title>Test if a field is SQL NULL</title>
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<h1 class="refname">pg_field_is_null</h1>
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5)</p><p class="refpurpose"><span class="refname">pg_field_is_null</span> — <span class="dc-title">Test if a field is SQL <em>NULL</em></span></p>
</div>
<div class="refsect1 description" id="refsect1-function.pg-field-is-null-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <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">$field</code></span>
)</div>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>pg_field_is_null</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$result</code></span>
, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$field</code></span>
)</div>
<p class="para rdfs-comment">
<span class="function"><strong>pg_field_is_null()</strong></span> tests if a field in a PostgreSQL
result resource is SQL <em>NULL</em> or not.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function used to be called <span class="function"><strong>pg_fieldisnull()</strong></span>.
</p>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-function.pg-field-is-null-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">result</code></em></span>
<dd>
<p class="para">
PostgreSQL query result resource, returned by <span class="function"><a href="function.pg-query.html" class="function">pg_query()</a></span>,
<span class="function"><a href="function.pg-query-params.html" class="function">pg_query_params()</a></span> or <span class="function"><a href="function.pg-execute.html" class="function">pg_execute()</a></span>
(among others).
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">row</code></em></span>
<dd>
<p class="para">
Row number in result to fetch. Rows are numbered from 0 upwards. If omitted,
current row is fetched.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">field</code></em></span>
<dd>
<p class="para">
Field number (starting from 0) as an <span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span> or
the field name as a <span class="type"><a href="language.types.string.html" class="type string">string</a></span>.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.pg-field-is-null-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <em>1</em> if the field in the given row is SQL <em>NULL</em>, <em>0</em>
if not. <strong><code>FALSE</code></strong> is returned if the row is out of range, or upon any other error.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.pg-field-is-null-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-2071">
<p><strong>Example #1 <span class="function"><strong>pg_field_is_null()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><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>
</code></div>
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