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Db::del
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#include <db_cxx.h>
int
Db::del(DbTxn *txnid, Dbt *key, u_int32_t flags);
Description
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 Db::associate method, the Db::del method deletes the
key/data pair from the primary database and all secondary indices.
If the operation is to be transaction-protected, the txnid
parameter is a transaction handle returned from DbEnv::txn_begin;
otherwise, NULL.
The flags parameter is currently unused, and must be set to 0.
The Db::del method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, 0 on success, and DB_NOTFOUND if the specified key did not exist in
the file.
Errors
The Db::del method may fail and throw an exception or return a non-zero error for the following conditions:
- DB_LOCK_DEADLOCK
- The operation was selected to resolve a deadlock.
- DB_SECONDARY_BAD
- A secondary index references a nonexistent primary key.
- EACCES
- An attempt was made to modify a read-only database.
- EINVAL
- An invalid flag value or parameter was specified.
The Db::del 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 Db::del method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.
Class
Db
See Also
Db::associate,
Db::close,
Db::cursor,
Db::del,
Db::err, Db::errx
Db::fd,
Db::get,
Db::pget,
Db::get_byteswapped,
Db::get_type,
Db::join,
Db::key_range,
Db::open,
Db::put,
Db::remove,
Db::rename,
Db::set_alloc,
Db::set_append_recno,
Db::set_bt_compare,
Db::set_bt_minkey,
Db::set_bt_prefix,
Db::set_cachesize,
Db::set_dup_compare,
Db::set_errcall,
Db::set_errfile,
Db::set_errpfx,
Db::set_feedback,
Db::set_flags,
Db::set_h_ffactor,
Db::set_h_hash,
Db::set_h_nelem,
Db::set_lorder,
Db::set_pagesize,
Db::set_paniccall,
Db::set_q_extentsize,
Db::set_re_delim,
Db::set_re_len,
Db::set_re_pad,
Db::set_re_source,
Db::stat,
Db::sync,
Db::truncate,
Db::upgrade,
and
Db::verify.
Copyright Sleepycat Software
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