Db API Ref

#include <db_cxx.h>

class Db { public: Db(DbEnv *dbenv, u_int32_t flags); ~Db();

DB *Db::get_DB(); const DB *Db::get_const_DB() const; static Db *Db::get_Db(DB *db); static const Db *Db::get_const_Db(const DB *db); ... };


Description: Db

The Db handle is the handle for a Berkeley DB database, which may or may not be part of a database environment.

Db handles are free-threaded if the DB_THREAD flag is specified to the Db::open method when the database is opened or if the database environment in which the database is opened is free-threaded. The handle should not be closed while any other handle that refers to the database is in use; for example, database handles must not be closed while cursor handles into the database remain open, or transactions that include operations on the database have not yet been committed or aborted. Once the Db::close, Db::remove, Db::rename, or Db::verify methods are called, the handle may not be accessed again, regardless of the method's return.

The constructor creates a Db object that is the handle for a Berkeley DB database. The constructor allocates memory internally; calling the Db::close, Db::remove or Db::rename methods will free that memory.

Each Db object has an associated DB struct, which is used by the underlying implementation of Berkeley DB and its C-language API. The Db::get_DB method returns a pointer to this struct. Given a const Db object, Db::get_const_DB returns a const pointer to the same struct.

Given a DB struct, the Db::get_Db method returns the corresponding Db object, if there is one. If the DB object was not associated with a Db (that is, it was not returned from a call to Db::get_DB), then the result of Db::get_Db is undefined. Given a const DB struct, Db::get_const_Db returns the associated const Db object, if there is one.

These methods may be useful for Berkeley DB applications including both C and C++ language software. It should not be necessary to use these calls in a purely C++ application.

Parameters
dbenv flags


Class Db
See Also Databases and Related Methods

APIRef

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