NdbBlob Types The NdbBlob::ActiveHook Type The NdbBlob::State Type


This section details the public types belonging to the NdbBlob class. The NdbBlob::ActiveHook Type


ActiveHook is a data type defined for use as a callback for the setActiveHook() method. (See Section, “NdbBlob::setActiveHook().)

Definition.  ActiveHook is a custom data type defined as shown here:

typedef int ActiveHook
      NdbBlob* me,
      void*    arg

Description.  This is a callback for NdbBlob::setActiveHook(), and is invoked immediately once the prepared operation has been executed (but not committed). Any calls to getValue() or setValue() are performed first. The BLOB handle is active so readData() or writeData() can be used to manipulate the BLOB value. A user-defined argument is passed along with the NdbBlob. setActiveHook() returns a nonzero value in the event of an error. The NdbBlob::State Type


This is an enumerated data type which represents the possible states of an NdbBlob instance.

Description.  An NdbBlob may assume any one of these states

Enumeration values.  Possible values are shown, along with descriptions, in the following table:

IdleThe NdbBlob has not yet been prepared for use with any operations.
PreparedThis is the state of the NdbBlob prior to operation execution.
ActiveThis is the BLOB handle's state following execution or the fetching of the next result, but before the transaction is committed.
ClosedThis state occurs after the transaction has been committed.
InvalidThis follows a rollback or the close of a transaction.