DbSequence::open
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#include <db_cxx.h>
int
int
DbSequence::open(DbTxn *txnid, Dbt *key, u_int32_t flags);
int
DbSequence::get_dbp(Db **dbp);
int
DbSequence::get_key(Dbt *key);
Description: DbSequence::open
The DbSequence::open method opens the sequence represented by the key.
The key must be compatible with the underlying database specified in the
corresponding call to db_sequence_create.
Parameters
- key
- The key specifies which record in the database stores
the persistent sequence data.
- flags
- The flags parameter must be set to 0 or by bitwise inclusively OR'ing together one
or more of the following values:
- DB_CREATE
- Create the sequence. If the sequence does not already exist and the
DB_CREATE flag is not specified, the DbSequence::open will fail.
- DB_EXCL
- Return an error if the sequence already exists. The DB_EXCL
flag is only meaningful when specified with the DB_CREATE
flag.
- DB_THREAD
- Cause the DbSequence handle returned by DbSequence::open to be
free-threaded; that is, usable by multiple threads within a
single address space. Note that if multiple threads create multiple
sequences using the same database handle that handle must have been
opened specifying DB_THREAD.
- txnid
- If the operation is part of an application-specified
transaction, the txnid parameter is a transaction handle
returned from DbEnv::txn_begin; otherwise NULL. If no transaction
handle is specified, but the
operation occurs in a transactional
database,
the operation will be implicitly transaction protected. Transactionally protected operations on a DbSequence handle
require the DbSequence handle itself be transactionally
protected during its open if the open creates the sequence.
Description: DbSequence::get_dbp
The DbSequence::get_dbp method returns the database handle.
Parameters
- dbp
- The dbp parameter references memory into which
a pointer to the database handle is copied.
The DbSequence::get_dbp method may be called at any time during the life of the
application.
The DbSequence::get_dbp 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.
Description: DbSequence::get_key
The DbSequence::get_key method returns the key for the sequence.
Parameters
- key
- The key parameter references memory into which
a pointer to the key data is copied.
The DbSequence::get_key method may be called at any time during the life of the
application.
The DbSequence::get_key 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.
Class
DbSequence
See Also
Sequences and Related Methods
Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.