DBcursor->del()

DBcursor->del()
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#include <db.h>

int
DBcursor->del(DBC *DBcursor, u_int32_t flags);

The DBcursor->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 DBcursor->del() method will return DB_KEYEMPTY if the element has already been deleted. The DBcursor->del() method returns a non-zero error value on failure and 0 on success.

Parameters

flags

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

DB_CONSUME

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.

Errors

The DBcursor->del() method may fail and return one of the following non-zero errors:

DB_FOREIGN_CONFLICT

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

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.
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.

DB_LOCK_DEADLOCK

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

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.

You attempted to open a database handle that is configured for no waiting exclusive locking, but the exclusive lock could not be immediately obtained. See DB->set_lk_exclusive() for more information.

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 return DB_REP_HANDLE_DEAD. The application will need to discard the handle and open a new one in order to continue processing.

DB_REP_LOCKOUT

The operation was blocked by client/master synchronization.

DB_SECONDARY_BAD

A secondary index references a nonexistent primary key.

EACCES

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

EINVAL

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

EPERM

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

Class

DBcursor

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