MySQL NDB Cluster API Developer Guide

2.3.21.11 NdbEventOperation::getPreValue()

Description.  This method performs identically to getValue(), except that it is used to define a retrieval operation of an attribute's previous value rather than the current value. See Section 2.3.21.13, “NdbEventOperation::getValue()”, for details.

Signature. 

NdbRecAttr* getPreValue
    (
      const char* name,
      char*       value = 0
    )

Parameters.  This method takes the two parameters listed here:

Return value.  An NdbRecAttr object to hold the value of the attribute, or a NULL pointer indicating that an error has occurred.