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diff --git a/bdb/docs/api_cxx/dbc_get.html b/bdb/docs/api_cxx/dbc_get.html deleted file mode 100644 index d42a194e514..00000000000 --- a/bdb/docs/api_cxx/dbc_get.html +++ /dev/null @@ -1,170 +0,0 @@ -<!--$Id: dbc_get.so,v 10.46 2001/01/19 17:29:46 bostic Exp $--> -<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> -<!--All rights reserved.--> -<html> -<head> -<title>Berkeley DB: Dbc::get</title> -<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> -<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++"> -</head> -<body bgcolor=white> - <a name="2"><!--meow--></a> -<table><tr valign=top> -<td> -<h1>Dbc::get</h1> -</td> -<td width="1%"> -<a href="../api_cxx/cxx_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> -</td></tr></table> -<hr size=1 noshade> -<tt> -<h3><pre> -#include <db_cxx.h> -<p> -int -Dbc::get(Dbt *key, Dbt *data, u_int32_t flags); -</pre></h3> -<h1>Description</h1> -<p>The Dbc::get method retrieves key/data pairs from the database. The -address and length of the key -are returned in the object referenced by <b>key</b> (except for the case -of the DB_SET flag where the <b>key</b> object is unchanged), -and the address and length of -the data are returned in the object referenced by <b>data</b>. -<p>Modifications to the database during a sequential scan will be reflected -in the scan, i.e. records inserted behind a cursor will not be returned -while records inserted in front of a cursor will be returned. -<p>In Queue and Recno databases, missing entries (i.e., entries that were -never explicitly created or that were created and then deleted), will be -skipped during a sequential scan. -<p>If multiple threads or processes insert items into the same database file -without using locking, the results are undefined. -For more detail, -see <a href="../ref/am/stability.html">Cursor stability</a>. -<p>The <b>flags</b> parameter must be set to one of the following values: -<p><dl compact> -<p><dt><a name="DB_CURRENT">DB_CURRENT</a><dd>Return the key/data pair currently referenced by the cursor. -<p>If the cursor key/data pair was deleted, Dbc::get will return -<a href="../ref/program/errorret.html#DB_KEYEMPTY">DB_KEYEMPTY</a>. -<p>If the cursor is not yet initialized, the Dbc::get method either returns EINVAL or throws an exception that encapsulates EINVAL. -<p><dt><a name="DB_FIRST">DB_FIRST</a>, <a name="DB_LAST">DB_LAST</a><dd>The cursor is set to reference the first (last) key/data pair of the -database, and that pair is returned. In the presence of duplicate key -values, the first (last) data item in the set of duplicates is returned. -<p>If the database is a Queue or Recno database, Dbc::get using the -DB_FIRST (DB_LAST) flags will ignore any keys that exist -but were never explicitly created by the application or were created and -later deleted. -<p>If the database is empty, Dbc::get will return <a href="../ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a>. -<p><dt><a name="DB_GET_BOTH">DB_GET_BOTH</a><dd>The DB_GET_BOTH flag is identical to the DB_SET flag, -except that both the key and the data arguments must be matched by the -key and data item in the database. -<p><dt><a name="DB_GET_RECNO">DB_GET_RECNO</a><dd>Return the record number associated with the cursor. The record number -will be returned in <b>data</b> as described in <a href="../api_cxx/dbt_class.html">Dbt</a>. The -<b>key</b> parameter is ignored. -<p>For DB_GET_RECNO to be specified, the underlying database must be -of type Btree and it must have been created with the <a href="../api_cxx/db_set_flags.html#DB_RECNUM">DB_RECNUM</a> -flag. -<p><dt><a name="DB_JOIN_ITEM">DB_JOIN_ITEM</a><dd>Do not use the data value found in all of the cursors as a lookup key for -the primary database, but simply return it in the key parameter instead. -The data parameter is left unchanged. -<p>For DB_JOIN_ITEM to be specified, the underlying cursor must have -been returned from the <a href="../api_cxx/db_join.html">Db::join</a> method. -<p><dt><a name="DB_NEXT">DB_NEXT</a>, <a name="DB_PREV">DB_PREV</a><dd>If the cursor is not yet initialized, DB_NEXT (DB_PREV) -is identical to DB_FIRST (DB_LAST). Otherwise, the cursor -is moved to the next (previous) key/data pair of the database, and that -pair is returned. In the presence of duplicate key values, the value of -the key may not change. -<p>If the database is a Queue or Recno database, Dbc::get using the -DB_NEXT (DB_PREV) flag will skip any keys that exist but -were never explicitly created by the application or were created and later -deleted. -<p>If the cursor is already on the last (first) record in the database, -Dbc::get will return <a href="../ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a>. -<p><dt><a name="DB_NEXT_DUP">DB_NEXT_DUP</a><dd>If the next key/data pair of the database is a duplicate record for the -current key/data pair, the cursor is moved to the next key/data pair of -the database, and that pair is returned. Otherwise, Dbc::get will -return <a href="../ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a>. -<p>If the cursor is not yet initialized, the Dbc::get method either returns EINVAL or throws an exception that encapsulates EINVAL. -<p><dt><a name="DB_NEXT_NODUP">DB_NEXT_NODUP</a>, <a name="DB_PREV_NODUP">DB_PREV_NODUP</a><dd>If the cursor is not yet initialized, DB_NEXT_NODUP -(DB_PREV_NODUP) is identical to DB_FIRST -(DB_LAST). Otherwise, the cursor is moved to the next (previous) -non-duplicate key/data pair of the database, and that pair is returned. -<p>If the database is a Queue or Recno database, Dbc::get using the -DB_NEXT_NODUP (DB_PREV_NODUP) flags will ignore any keys -that exist but were never explicitly created by the application or were -created and later deleted. -<p>If no non-duplicate key/data pairs occur after (before) the cursor -position in the database, Dbc::get will return <a href="../ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a>. -<p><dt><a name="DB_SET">DB_SET</a><dd>Move the cursor to the specified key/data pair of the database, and -return the datum associated with the given key. -<p>In the presence of duplicate key values, Dbc::get will return the -first data item for the given key. -<p>If the database is a Queue or Recno database and the requested key exists, -but was never explicitly created by the application or was later deleted, -Dbc::get will return <a href="../ref/program/errorret.html#DB_KEYEMPTY">DB_KEYEMPTY</a>. -<p>If no matching keys are found, Dbc::get will return -<a href="../ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a>. -<p><dt><a name="DB_SET_RANGE">DB_SET_RANGE</a><dd>The DB_SET_RANGE flag is identical to the DB_SET flag, -except that the key is returned as well as the data item, and, in the case -of the Btree access method, the returned key/data pair is the smallest -key greater than or equal to the specified key (as determined by the -comparison method), permitting partial key matches and range -searches. -<p><dt><a name="DB_SET_RECNO">DB_SET_RECNO</a><dd>Move the cursor to the specific numbered record of the database, and -return the associated key/data pair. The <b>data</b> field of the -specified <b>key</b> -must be a pointer to a memory location from which a <a href="../api_cxx/dbt_class.html#db_recno_t">db_recno_t</a> -may be read, as described in <a href="../api_cxx/dbt_class.html">Dbt</a>. This memory location will be -read to determine the record to be retrieved. -<p>For DB_SET_RECNO to be specified, the underlying database must be -of type Btree and it must have been created with the <a href="../api_cxx/db_set_flags.html#DB_RECNUM">DB_RECNUM</a> -flag. -</dl> -<p>In addition, the following flag may be set by bitwise inclusively <b>OR</b>'ing it into the -<b>flags</b> parameter: -<p><dl compact> -<p><dt><a name="DB_RMW">DB_RMW</a><dd>Acquire write locks instead of read locks when doing the retrieval. -Setting this flag may decrease the likelihood of deadlock during a -read-modify-write cycle by immediately acquiring the write lock during -the read part of the cycle so that another thread of control acquiring -a read lock for the same item, in its own read-modify-write cycle, will -not result in deadlock. -</dl> -<p>Otherwise, the Dbc::get method either returns a non-zero error value or throws an exception that -encapsulates a non-zero error value on failure, and returns 0 on success. -<p>If Dbc::get fails for any reason, the state of the cursor will be -unchanged. -<h1>Errors</h1> -<p>The Dbc::get method may fail and throw an exception or return a non-zero error for the following conditions: -<p><dl compact> -<p><dt>DB_LOCK_DEADLOCK<dd>The operation was selected to resolve a deadlock. -</dl> -<p><dl compact> -<p><dt>ENOMEM<dd>There was insufficient memory to return the requested item. -</dl> -<p><dl compact> -<p><dt>EINVAL<dd>An invalid flag value or parameter was specified. -<p>The specified cursor was not currently initialized. -</dl> -<p>The Dbc::get method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods. -If a catastrophic error has occurred, the Dbc::get method may fail and either -return <a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a> or throw an exception encapsulating -<a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>, in which case all subsequent Berkeley DB calls will fail -in the same way. -<h3>Class</h3> -<a href="../api_cxx/dbc_class.html">Dbc</a> -<h1>See Also</h1> -<a href="../api_cxx/dbc_close.html">Dbc::close</a>, -<a href="../api_cxx/dbc_count.html">Dbc::count</a>, -<a href="../api_cxx/dbc_del.html">Dbc::del</a>, -<a href="../api_cxx/dbc_dup.html">Dbc::dup</a>, -<a href="../api_cxx/dbc_get.html">Dbc::get</a> -and -<a href="../api_cxx/dbc_put.html">Dbc::put</a>. -</tt> -<table><tr><td><br></td><td width="1%"> -<a href="../api_cxx/cxx_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> -</td></tr></table> -<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> -</body> -</html> |