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Db::del
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<pre>
#include &lt;db_cxx.h&gt;

int
Db::del(DbTxn *txnid, Dbt *key, u_int32_t flags);
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Description: Db::del
The Db::del method removes key/data pairs from the database. The
key/data pair associated with the specified key is discarded from
the database. In the presence of duplicate key values, all records
associated with the designated key will be discarded.
When called on a database that has been made into a secondary index
using the <a href="../../db4-devel-4.7.25/api_cxx/db_associate.html">Db::associate</a> method, the Db::del method deletes the
key/data pair from the primary database and all secondary indices.
The Db::del method will return <a href="../../db4-devel-4.7.25/ref/program/errorret.html#DB_NOTFOUND">DB_NOTFOUND</a> if the specified key is not in the database.
The Db::del method will return <a href="../../db4-devel-4.7.25/ref/program/errorret.html#DB_KEYEMPTY">DB_KEYEMPTY</a> if the database is a Queue or Recno database and
the specified key exists, but was never explicitly created by the
application or was later deleted.
Unless otherwise specified, the Db::del 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.

Parameters 
 flags<ul compact><li>The flags parameter is currently unused, and must be set to 0.</ul>
 key<ul compact><li>The key <a href="../../db4-devel-4.7.25/api_cxx/dbt_class.html">Dbt</a> operated on.</ul>
 txnid<ul compact><li>If the operation is part of an application-specified transaction, the
txnid parameter is a transaction handle returned from
<a href="../../db4-devel-4.7.25/api_cxx/txn_begin.html">DbEnv::txn_begin</a>; if the operation is part of a Berkeley DB Concurrent Data Store group, the
txnid parameter is a handle returned from
<a href="../../db4-devel-4.7.25/api_cxx/env_cdsgroup_begin.html">DbEnv::cdsgroup_begin</a>; otherwise NULL.
If no transaction handle is
specified, but the
operation occurs in a transactional
database,
the operation will be implicitly transaction protected.
</ul>
 
 Errors
The Db::del method
may fail and throw
<a href="../../db4-devel-4.7.25/api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:
 
DB_REP_HANDLE_DEAD<ul compact><li>The database handle has been invalidated because a replication election
unrolled a committed transaction.</ul>
 
 
DB_REP_LOCKOUT<ul compact><li>The operation was blocked by client/master synchronization.</ul>
 
 
DB_SECONDARY_BAD<ul compact><li>A secondary index references a nonexistent primary key.</ul>
 
 
EACCES<ul compact><li>An attempt was made to modify a read-only database.</ul>
 
 
EINVAL<ul compact><li>An
invalid flag value or parameter was specified.</ul>
 
If a transactional database environment operation was selected to
resolve a deadlock, the Db::del method will fail and
either return <a href="../../db4-devel-4.7.25/ref/program/errorret.html#DB_LOCK_DEADLOCK">DB_LOCK_DEADLOCK</a> or
throw a <a href="../../db4-devel-4.7.25/api_cxx/deadlock_class.html">DbDeadlockException</a> exception.
If a Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable
to grant a lock in the allowed time, the Db::del method will fail and
either return <a href="../../db4-devel-4.7.25/ref/program/errorret.html#DB_LOCK_NOTGRANTED">DB_LOCK_NOTGRANTED</a> or
throw a <a href="../../db4-devel-4.7.25/api_cxx/lockng_class.html">DbLockNotGrantedException</a> exception.
<hr size=1 noshade>
 Class
<a href="../../db4-devel-4.7.25/api_cxx/db_class.html">Db</a>
 See Also
<a href="../../db4-devel-4.7.25/api_cxx/db_list.html">Databases and Related Methods</a>
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