#include <db_cxx.h>

int Db::cursor(DbTxn *txnid, Dbc **cursorp, u_int32_t flags);


The Db::cursor method creates a cursor and copies a pointer to it into the memory to which cursorp refers.

If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DbEnv::txn_begin; otherwise, NULL.

To transaction-protect cursor operations, cursors must be opened and closed within the context of a transaction, and the txnid parameter specifies the transaction context in which the cursor may be used.

The flags value must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

All read operations performed by the cursor may return modified but not yet committed data. Silently ignored if the DB_DIRTY_READ flag was not specified when the underlying database was opened.

Specify that the cursor will be used to update the database. The underlying database environment must have been opened using the DB_INIT_CDB flag.

The Db::cursor 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 Db::cursor method may fail and throw an exception or return a non-zero error for the following conditions:

An invalid flag value or parameter was specified.

The Db::cursor 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::cursor method may fail and either return DB_RUNRECOVERY or throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.



See Also

Database Cursors and Related Methods


Copyright Sleepycat Software