Berkeley DB: DB->cursor
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

### DB->cursor |

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###

    #include <db.h>

    int
    DB->cursor(DB *db,
        DB_TXN *txnid, DBC **cursorp, u_int32_t flags);

### Description: DB->cursor

The DB->cursor method returns a created database cursor.

The DB->cursor method returns a non-zero error value on failure and 0 on success.

### Parameters

cursorp
  The cursorp parameter references memory into which a pointer to the allocated cursor is copied.
flags
  The flags parameter must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:
  DB_DEGREE_2
    This cursor will have degree 2 isolation. This ensures the stability of the current data item read by this cursor but permits data read by this cursor to be modified or deleted prior to the commit of the transaction for this cursor.
  DB_DIRTY_READ
    All read operations performed by the cursor may return modified but not yet committed data. Silently ignored if the DB_DIRTY_READ flag was not specified when the underlying database was opened.
  DB_WRITECURSOR
    Specify that the cursor will be used to update the database. The underlying database environment must have been opened using the DB_INIT_CDB flag.
txnid
  If the operation is to be transaction-protected, the txnid parameter is a transaction handle returned from DB_ENV->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.

### Errors

The DB->cursor method may fail and return one of the following non-zero errors:

DB_REP_HANDLE_DEAD
  The database handle has been invalidated because a replication election unrolled a committed transaction.

EINVAL
  An invalid flag value or parameter was specified.

### Class

DBC

### See Also

Database Cursors and Related Methods`

Copyright (c) 1996-2004 Sleepycat Software, Inc. - All rights reserved.