jdbc-protolib/src/main/java/com/streamsets/pipeline/lib/jdbc/JdbcRecordReader.java
String getFieldPath(String columnName, Map<String, String> columnsToField, int op){
    return columnsToField.get(columnName);
  }
String getFieldPath(String columnName, Map<String, String> columnsToField, int op){
    return columnsToField.get(columnName);
  }
This function simply returns field path in record for the corresponding column name.
This is needed because records generated by CDC origins store data in different location
for different operation. Subclasses will override this function and implement special handling.
@param columnName column name
@param columnsToField mapping of column name to field path
@param op  Not used here but is used in subclass.
@return