Berkeley DB: Db.cursor
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++

# Db.cursor |

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    import com.sleepycat.db.*;

    public Dbc cursor(DbTxn txnid, int flags)
        throws DbException;

# Description

The Db.cursor method creates a cursor.

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:

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

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

The Db.cursor method throws an exception that encapsulates a non-zero error value on failure.

# Errors

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

EINVAL
  An invalid flag value or parameter was specified.

The Db.cursor method may fail and throw an exception 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 throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

Db

# See Also

Db.associate, Db.close, Db.cursor, Db.del, Db.fd, Db.get, Db.pget, Db.get_byteswapped, Db.get_type, Db.join, Db.key_range, Db.open, Db.put, Db.remove, Db.rename, Db.set_append_recno, Db.set_bt_minkey, Db.set_cachesize, Db.set_errcall, Db.set_errpfx, Db.set_feedback, Db.set_flags, Db.set_h_ffactor, Db.set_h_nelem, Db.set_lorder, Db.set_pagesize, Db.set_q_extentsize, Db.set_re_delim, Db.set_re_len, Db.set_re_pad, Db.set_re_source, Db.stat, Db.sync, Db.truncate, Db.upgrade, and Db.verify.`

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