<!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>Seeks position within a large object</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.pg-lo-read.html">pg_lo_read</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.pg-lo-tell.html">pg_lo_tell</a></div>
<div class="up"><a href="ref.pgsql.html">PostgreSQL Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="function.pg-lo-seek" class="refentry">
<div class="refnamediv">
<h1 class="refname">pg_lo_seek</h1>
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5)</p><p class="refpurpose"><span class="refname">pg_lo_seek</span> — <span class="dc-title">
Seeks position within a large object
</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.pg-lo-seek-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>pg_lo_seek</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$large_object</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$offset</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$whence</code><span class="initializer"> = PGSQL_SEEK_CUR</span></span>
] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>pg_lo_seek()</strong></span> seeks a position within a large object
resource.
</p>
<p class="para">
To use the large object interface, it is necessary to
enclose it within a transaction block.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.pg-lo-seek-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">large_object</code></em></span>
<dd>
<p class="para">
PostgreSQL large object (LOB) resource, returned by <span class="function"><a href="function.pg-lo-open.html" class="function">pg_lo_open()</a></span>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">offset</code></em></span>
<dd>
<p class="para">
The number of bytes to seek.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">whence</code></em></span>
<dd>
<p class="para">
One of the constants <strong><code>PGSQL_SEEK_SET</code></strong> (seek from object start),
<strong><code>PGSQL_SEEK_CUR</code></strong> (seek from current position)
or <strong><code>PGSQL_SEEK_END</code></strong> (seek from object end) .
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.pg-lo-seek-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.pg-lo-seek-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-2095">
<p><strong>Example #1 <span class="function"><strong>pg_lo_seek()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /> $doc_oid </span><span style="color: #007700">= </span><span style="color: #0000BB">189762345</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$database </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=jacarta"</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">pg_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$database</span><span style="color: #007700">, </span><span style="color: #DD0000">"begin"</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$handle </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_lo_open</span><span style="color: #007700">(</span><span style="color: #0000BB">$database</span><span style="color: #007700">, </span><span style="color: #0000BB">$doc_oid</span><span style="color: #007700">, </span><span style="color: #DD0000">"r"</span><span style="color: #007700">);<br /> </span><span style="color: #FF8000">// Skip first 50000 bytes<br /> </span><span style="color: #0000BB">pg_lo_seek</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">, </span><span style="color: #0000BB">50000</span><span style="color: #007700">, </span><span style="color: #0000BB">PGSQL_SEEK_SET</span><span style="color: #007700">);<br /> </span><span style="color: #FF8000">// Read the next 10000 bytes<br /> </span><span style="color: #0000BB">$data </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_lo_read</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">, </span><span style="color: #0000BB">10000</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">pg_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$database</span><span style="color: #007700">, </span><span style="color: #DD0000">"commit"</span><span style="color: #007700">);<br /> echo </span><span style="color: #0000BB">$data</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.pg-lo-seek-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.pg-lo-tell.html" class="function" rel="rdfs-seeAlso">pg_lo_tell()</a> - Returns current seek position a of large object</span></li>
</ul>
</p>
</div>
</div><hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.pg-lo-read.html">pg_lo_read</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.pg-lo-tell.html">pg_lo_tell</a></div>
<div class="up"><a href="ref.pgsql.html">PostgreSQL Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
