# Db::del

`

###

    #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.

If the file is being accessed under transaction protection, the txnid parameter is a transaction ID 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 returns 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.

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::close, Db::cursor, Db::del, Db::err, Db::fd, Db::get, Db::get_byteswapped, Db::get_type, Db::join, Db::key_range, Db::open, Db::put, Db::remove, 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_flags, Db::set_h_ffactor, Db::set_h_hash, Db::set_h_nelem, Db::set_lorder, Db::set_malloc, Db::set_pagesize, Db::set_paniccall, Db::set_realloc, Db::set_re_delim, Db::set_re_len, Db::set_re_pad, Db::set_re_source, Db::stat, Db::sync, Db::upgrade and Db::verify.`

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