Berkeley DB: Db::del
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

### Db::del |

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###

    #include <db_cxx.h>

    int
    Db::del(DbTxn *txnid, Dbt *key, u_int32_t flags);

### 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 Db::associate method, the Db::del method deletes the key/data pair from the primary database and all secondary indices.

The Db::del method will return DB_NOTFOUND if the specified key is not in the database. The Db::del method will return DB_KEYEMPTY 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

key
  The key Dbt operated on.

flags
  The flags parameter must be set to 0 or the following value:

  DB_AUTO_COMMIT
    Enclose the Db::del call within a transaction. If the call succeeds, changes made by the operation will be recoverable. If the call fails, the operation will have made no changes.

txnid
  If the operation is to be transaction-protected, (other than by specifying the DB_AUTO_COMMIT flag), the txnid parameter is a transaction handle returned from DbEnv::txn_begin; otherwise, NULL.

### Errors

The Db::del method may fail and throw DbException, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

DB_REP_HANDLE_DEAD
  The database handle has been invalidated because a replication election unrolled a committed transaction.

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.

If a transactional database environment operation was selected to resolve a deadlock, the Db::del method will fail and either return DB_LOCK_DEADLOCK or throw a DbDeadlockException 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 DB_LOCK_NOTGRANTED or throw a DbLockNotGrantedException exception.

### Class

Db

### See Also

Databases and Related Methods`

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