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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Creates a new large object</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.pdo-pgsql.connection.html">PDO_PGSQL DSN</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.pdo-pgsqllobopen.html">PDO::pgsqlLOBOpen</a></div> <div class="up"><a href="ref.pdo-pgsql.html">PostgreSQL (PDO)</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.pdo-pgsqllobcreate" class="refentry"> <div class="refnamediv"> <h1 class="refname">PDO::pgsqlLOBCreate</h1> <p class="verinfo">(PHP 5 >= 5.1.2, PECL pdo_pgsql:1.0.1-1.0.2)</p><p class="refpurpose"><span class="refname">PDO::pgsqlLOBCreate</span> — <span class="dc-title">Creates a new large object</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">string</span> <span class="methodname"><b><b>PDO::pgsqlLOBCreate</b></b></span> ( <span class="methodparam">void</span> )</div> <p class="para rdfs-comment"> <b>PDO::pgsqlLOBCreate()</b> creates a large object and returns the OID of that object. You may then open a stream on the object using <a href="function.pdo-pgsqllobopen.html" class="function">PDO::pgsqlLOBOpen()</a> to read or write data to it. The OID can be stored in columns of type OID and be used to reference the large object, without causing the row to grow arbitrarily large. The large object will continue to live in the database until it is removed by calling <a href="function.pdo-pgsqllobunlink.html" class="function">PDO::pgsqlLOBUnlink()</a>. </p> <p class="para"> Large objects can be up to 2GB in size, but are cumbersome to use; you need to ensure that <a href="function.pdo-pgsqllobunlink.html" class="function">PDO::pgsqlLOBUnlink()</a> is called prior to deleting the last row that references its OID from your database. In addition, large objects have no access controls. As an alternative, try the bytea column type; recent versions of PostgreSQL allow bytea columns of up to 1GB in size and transparently manage the storage for optimal row size. </p> <blockquote><p><b class="note">Note</b>: <span class="simpara"> This function must be called within a transaction. </span> </p></blockquote> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <b>PDO::pgsqlLOBCreate()</b> takes no parameters. </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns the OID of the newly created large object on success, or <b><tt>FALSE</tt></b> on failure. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 A <b>PDO::pgsqlLOBCreate()</b> example</b></p> <div class="example-contents"><p> This example creates a new large object and copies the contents of a file into it. The OID is then stored into a table. </p></div> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$db </span><span style="color: #007700">= new </span><span style="color: #0000BB">PDO</span><span style="color: #007700">(</span><span style="color: #DD0000">'pgsql:dbname=test host=localhost'</span><span style="color: #007700">, </span><span style="color: #0000BB">$user</span><span style="color: #007700">, </span><span style="color: #0000BB">$pass</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">setAttribute</span><span style="color: #007700">(</span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">ATTR_ERRMODE</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">ERRMODE_EXCEPTION</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">beginTransaction</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">$oid </span><span style="color: #007700">= </span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">pgsqlLOBCreate</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">$stream </span><span style="color: #007700">= </span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">pgsqlLOBOpen</span><span style="color: #007700">(</span><span style="color: #0000BB">$oid</span><span style="color: #007700">, </span><span style="color: #DD0000">'w'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$local </span><span style="color: #007700">= </span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">, </span><span style="color: #DD0000">'rb'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">stream_copy_to_stream</span><span style="color: #007700">(</span><span style="color: #0000BB">$local</span><span style="color: #007700">, </span><span style="color: #0000BB">$stream</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$local </span><span style="color: #007700">= </span><span style="color: #0000BB">null</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$stream </span><span style="color: #007700">= </span><span style="color: #0000BB">null</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$stmt </span><span style="color: #007700">= </span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">"INSERT INTO BLOBS (ident, oid) VALUES (?, ?)"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">(array(</span><span style="color: #0000BB">$some_id</span><span style="color: #007700">, </span><span style="color: #0000BB">$oid</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">commit</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.pdo-pgsqllobopen.html" class="function" rel="rdfs-seeAlso">PDO::pgsqlLOBOpen()</a></li> <li class="member"><a href="function.pdo-pgsqllobunlink.html" class="function" rel="rdfs-seeAlso">PDO::pgsqlLOBUnlink()</a></li> <li class="member"><a href="function.pg-lo-create.html" class="function" rel="rdfs-seeAlso">pg_lo_create()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.pdo-pgsql.connection.html">PDO_PGSQL DSN</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.pdo-pgsqllobopen.html">PDO::pgsqlLOBOpen</a></div> <div class="up"><a href="ref.pdo-pgsql.html">PostgreSQL (PDO)</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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