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2.5 KiB
HTML
<!--$Id: get.so,v 10.15 2000/12/18 21:05:13 bostic Exp $-->
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<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.-->
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<!--All rights reserved.-->
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<html>
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<head>
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<title>Berkeley DB Reference Guide: Retrieving records</title>
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<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
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<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++">
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</head>
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<body bgcolor=white>
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<a name="2"><!--meow--></a>
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<table><tr valign=top>
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<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></h3></td>
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<td width="1%"><a href="../../ref/am/upgrade.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/am/put.html"><img src="../../images/next.gif" alt="Next"></a>
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</td></tr></table>
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<p>
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<h1 align=center>Retrieving records</h1>
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<p>The <a href="../../api_c/db_get.html">DB->get</a> function is the standard interface for retrieving records from
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the database. In general, <a href="../../api_c/db_get.html">DB->get</a> takes a key and returns the
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associated data from the database.
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<p>There are a few flags that you can set to customize retrieval:
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<p><dl compact>
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<p><dt><a href="../../api_c/db_get.html#DB_GET_BOTH">DB_GET_BOTH</a><dd>Search for a matching key and data item, i.e., only return success if both
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the key and the data items match those stored in the database.
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<p><dt><a href="../../api_c/dbc_get.html#DB_RMW">DB_RMW</a><dd>Read-modify-write: acquire write locks instead of read locks during
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retrieval. This can enhance performance in threaded applications by
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reducing the chance of deadlock.
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<p><dt><a href="../../api_c/db_get.html#DB_SET_RECNO">DB_SET_RECNO</a><dd>If the underlying database is a Btree, and was configured so that it
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is possible to search it by logical record number, retrieve a specific
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record.
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</dl>
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<p>If the database has been configured to support duplicate records,
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<a href="../../api_c/db_get.html">DB->get</a> will always return the first data item in the duplicate
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set.
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<table><tr><td><br></td><td width="1%"><a href="../../ref/am/upgrade.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/am/put.html"><img src="../../images/next.gif" alt="Next"></a>
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</td></tr></table>
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<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font>
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