#include <db_cxx.h>
Dbc::del(u_int32_t flags);

The Dbc::del() method deletes the key/data pair to which the cursor refers.

When called on a cursor opened 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 cursor position is unchanged after a delete, and subsequent calls to cursor functions expecting the cursor to refer to an existing key will fail.

The Dbc::del() method will return DB_KEYEMPTY if the element has already been deleted. The Dbc::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.



The flags parameter must be set to 0 or one of the following values:


    If the database is of type DB_QUEUE then this flag may be set to force the head of the queue to move to the first non-deleted item in the queue. Normally this is only done if the deleted item is exactly at the head when deleted.


The Dbc::del() method may fail and throw a DbException exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:


A foreign key constraint violation has occurred. This can be caused by one of two things:

  1. An attempt was made to add a record to a constrained database, and the key used for that record does not exist in the foreign key database.

  2. DB_FOREIGN_ABORT was declared for a foreign key database, and then subsequently a record was deleted from the foreign key database without first removing it from the constrained secondary database.

DbDeadlockException or DB_LOCK_DEADLOCK

A transactional database environment operation was selected to resolve a deadlock.

DbDeadlockException is thrown if your Berkeley DB API is configured to throw exceptions. Otherwise, DB_LOCK_DEADLOCK is returned.

DbLockNotGrantedException or DB_LOCK_NOTGRANTED

A Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time.

DbLockNotGrantedException is thrown if your Berkeley DB API is configured to throw exceptions. Otherwise, DB_LOCK_NOTGRANTED is returned.

DbRepHandleDeadException or DB_REP_HANDLE_DEAD

When a client synchronizes with the master, it is possible for committed transactions to be rolled back. This invalidates all the database and cursor handles opened in the replication environment. Once this occurs, an attempt to use such a handle will throw a DbRepHandleDeadException (if your application is configured to throw exceptions), or return DB_REP_HANDLE_DEAD. The application will need to discard the handle and open a new one in order to continue processing.

DbDeadlockException or DB_REP_LOCKOUT

The operation was blocked by client/master synchronization.

DbDeadlockException is thrown if your Berkeley DB API is configured to throw exceptions. Otherwise, DB_REP_LOCKOUT is returned.


A secondary index references a nonexistent primary key.


An attempt was made to modify a read-only database.


If the cursor has not been initialized; or if an invalid flag value or parameter was specified.


Write attempted on read-only cursor when the DB_INIT_CDB flag was specified to DbEnv::open().



See Also

Database Cursors and Related Methods