stagesupport/src/main/java/com/streamsets/pipeline/lib/operation/MySQLBinLogFieldConverter.java
@Override
  public String getFieldPath(String fieldPath, int operation) {
    if (operation == OperationType.DELETE_CODE) {
      return fieldPath.replace(DATA_FIELD, OLDDATA_FIELD);
    }
    return fieldPath;
  }
@Override
  public String getFieldPath(String fieldPath, int operation) {
    if (operation == OperationType.DELETE_CODE) {
      return fieldPath.replace(DATA_FIELD, OLDDATA_FIELD);
    }
    return fieldPath;
  }
This is used by destination which performs CRUD operations.
Records sent from MySQLBinLog origin have /Data field that contains a map of
key-value for INSERT and UPDATE operation, but
/OldData field for DELETE operation.
This method looks into /OldData for DELETE operation so that users don't
need a separate field-column mapping for DELETE.
@param fieldPath fieldPath specified in field-column mapping
@param operation Crud operation code
@return Actual field path in record