Berkeley DB: Db.cursor
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btr ee,hash,hashing,transaction,transactions,locking,logging,access method,access me thods,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.

A cursor is a structure used to provide sequential access through a database. This interface and its associated functions replaces the functionality provided by the seq function in previous releases of Berkeley DB.

If the file is being accessed under transaction protection, the txnid parameter is a transaction ID returned from DbTxnMgr.begin, otherwise, NULL. If transaction protection is enabled, 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 parameter must be set to 0.

In addition, the following value may be set by logically OR'ing it into the flags parameter:

DB_RMW
  Specify that the cursor will be used to update the database. This flag should only be set when the Db.DB_INIT_CDB flag was specified to DbEnv.appinit.

The Db.cursor method throws an exception that encapsulates an errno on failure.

# Errors

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

The Db.cursor method may fail and throw an exception for any of the errors specified for the following Berkeley DB and C library functions: __ham_c_init(3), free(3), DbLockTab.id, malloc(3), memcpy(3), and memset(3).

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

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.`