Berkeley DB: Db.del
Полезная информация

Db.del


import com.sleepycat.db.*;

public void del(DbTxn txnid, Dbt key, int flags) throws DbException;

Description

The Db.del method removes key/data pairs from the database. The key/data pair associated with the specified key is discarded from the database. In the presence of duplicate key values, all records associated with the designated key will be discarded.

If the file is being accessed under transaction protection, the txnid parameter is a transaction ID returned from DbTxnMgr.begin, otherwise, NULL.

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

The Db.del method throws an exception that encapsulates an errno on failure, and DB_NOTFOUND if the specified key did not exist in the file.

Errors

If a fatal error occurs in Berkeley DB, the Db.del method may fail and throw a DbRunRecoveryException, at which point all subsequent database calls will also fail in the same way.

The Db.del method may fail and throw an exception for any of the errors specified for the following Berkeley DB and C library functions: Db.cursor, DBcursor->c_close(3), DBcursor->c_del(3), Dbc.get, __account_page(3), dbenv->db_paniccall(3), fflush(3), fprintf(3), free(3), func(3), hcp->dbc->dbp->h_hash(3), DbLockTab.get, DbLock.put, DbLockTab.vec, DbLog.put, malloc(3), memcmp(3), memcpy(3), memmove(3), DbMpoolFile.get, DbMpoolFile.put, DbMpoolFile.set, memset(3), realloc(3), strerror(3), vfprintf(3), and vsnprintf(3).

In addition, the Db.del method may fail and throw an exception encapsulating errno for the following conditions:

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

EINVAL
An invalid flag value or parameter was specified.

Class

Db

See Also

Db.close, Db.cursor, Db.del, Db.fd, Db.get, Db.get_byteswapped, Db.get_type, Db.join, Db.open, Db.put, Db.stat and Db.sync.