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 |

`

###

    #include <db_cxx.h>

    int
    Db::cursor(DbTxn *txnid, Dbc **cursorp, u_int32_t flags);

### Description: Db::cursor

The Db::cursor method returns a created database cursor.

The Db::cursor method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 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_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 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.

### Errors

The Db::cursor method may fail and throw DbException, encapsulating one of the following non-zero errors, or 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`

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