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<! "@(#)del.so 10.9 (Sleepycat) 10/2/98">
<!Copyright 1997, 1998 by Sleepycat Software, Inc. All rights reserved.>
<html>
<body bgcolor=white>
<head>
<title>Berkeley DB: DB->del</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btr
ee,hash,hashing,transaction,transactions,locking,logging,access method,access me
thods,java,C,C++">
</head>
<h1>DB->del</h1>
<hr size=1 noshade>
<tt>
<h3>
<pre>
#include <db.h>
<p>
int
DB->del(DB *db, DB_TXN *txnid, DBT *key, u_int32_t flags);
</pre>
</h3>
<h1>Description</h1>
<p>
The DB->del function removes key/data pairs from the database.
The key/data pair associated with the specified <b>key</b> is discarded
from the database.
In the presence of duplicate key values, all records associated with the
designated key will be discarded.
<p>
If the file is being accessed under transaction protection,
the <b>txnid</b> parameter is a transaction ID returned from
<a href="../../api_c/DbTxnMgr/begin.html">txn_begin</a>, otherwise, NULL.
<p>
The <b>flags</b> parameter is currently unused, and must be set to 0.
<p>
The DB->del
function returns the value of <b>errno</b> on failure, 0 on success,
and DB_NOTFOUND if the specified <b>key</b> did not exist in the file.
<p>
<h1>Errors</h1>
If a fatal error occurs in Berkeley DB, the DB->del function may fail and return
DB_RUNRECOVERY, at which point all subsequent database calls will also
return DB_RUNRECOVERY.
<p>
The DB->del
function may fail and return <b>errno</b>
for any of the errors specified for the following Berkeley DB and C library
functions:
<a href="../../api_c/Db/cursor.html">DB->cursor</a>,
DBcursor->c_close(3),
DBcursor->c_del(3),
<a href="../../api_c/Dbc/get.html">DBcursor->c_get</a>,
__account_page(3),
dbenv->db_paniccall(3),
fflush(3),
fprintf(3),
free(3),
func(3),
hcp->dbc->dbp->h_hash(3),
<a href="../../api_c/DbLockTab/get.html">lock_get</a>,
<a href="../../api_c/DbLock/put.html">lock_put</a>,
<a href="../../api_c/DbLockTab/vec.html">lock_vec</a>,
<a href="../../api_c/DbLog/put.html">log_put</a>,
malloc(3),
memcmp(3),
memcpy(3),
memmove(3),
<a href="../../api_c/DbMpoolFile/get.html">memp_fget</a>,
<a href="../../api_c/DbMpoolFile/put.html">memp_fput</a>,
<a href="../../api_c/DbMpoolFile/set.html">memp_fset</a>,
memset(3),
realloc(3),
strerror(3),
vfprintf(3),
and
vsnprintf(3).
<p>
In addition, the DB->del
function may fail and return <b>errno</b>
for the following conditions:
<p>
<dl compact>
<p><dt>EACCES<dd>An attempt was made to modify a read-only database.
</dl>
<p>
<dl compact>
<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
<p>
</dl>
<p>
<h1>See Also</h1>
<a href="../../api_c/DbEnv/appexit.html">db_appexit</a>,
<a href="../../api_c/DbEnv/appinit.html">db_appinit</a>,
<a href="../../api_c/DbEnv/version.html">db_version</a>,
<a href="../../api_c/Db/close.html">DB->close</a>,
<a href="../../api_c/Db/cursor.html">DB->cursor</a>,
DB->del,
<a href="../../api_c/Db/fd.html">DB->fd</a>,
<a href="../../api_c/Db/get.html">DB->get</a>,
<a href="../../api_c/Db/join.html">DB->join</a>,
<a href="../../api_c/Db/open.html">db_open</a>,
<a href="../../api_c/Db/put.html">DB->put</a>,
<a href="../../api_c/Db/stat.html">DB->stat</a>,
<a href="../../api_c/Db/sync.html">DB->sync</a>,
<a href="../../api_c/Dbc/close.html">DBcursor->c_close</a>,
<a href="../../api_c/Dbc/del.html">DBcursor->c_del</a>,
<a href="../../api_c/Dbc/get.html">DBcursor->c_get</a>
and
<a href="../../api_c/Dbc/put.html">DBcursor->c_put</a>.
</tt>
</body>
</html>
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