Db::truncate |

`

    #include <db_cxx.h>

    int
    Db::truncate(DbTxn *txnid, u_int32_t *countp, u_int32_t flags);

Description: Db::truncate

The Db::truncate method empties the database, discarding all records it contains. The number of records discarded from the database is returned in countp.

When called on a database configured with secondary indices using the Db::associate method, the Db::truncate method truncates the primary database and all secondary indices. A count of the records discarded from the primary database is returned.

It is an error to call the Db::truncate method on a database with open cursors.

The Db::truncate 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
countp

- The countp parameter references memory into which the number of records discarded from the database is copied.

flags

- The flags parameter is currently unused, and must be set to 0.

txnid

- If the operation is part of an application-specified transaction, the txnid parameter is a transaction handle returned from DbEnv::txn_begin; if the operation is part of a Berkeley DB Concurrent Data Store group, the txnid parameter is a handle returned from DbEnv::cdsgroup_begin; otherwise NULL. If no transaction handle is specified, but the operation occurs in a transactional database, the operation will be implicitly transaction protected.

Errors

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

EINVAL

- If there are open cursors in the database; or if an invalid flag value or parameter was specified.

If a transactional database environment operation was selected to resolve a deadlock, the Db::truncate 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::truncate 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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