/// <summary>
 /// get list of CTree_expression by field
 /// </summary>
 /// <param name="fieldName">field name</param>
 /// <param name="value">value</param>
 /// <returns>list</returns>
 public List <CTree_expression> GetAllBy(CTree_expression.CTree_expressionFields fieldName, object value)
 {
     return(_dataObject.SelectByField(fieldName.ToString(), value));
 }
 /// <summary>
 /// delete CTree_expression by field.
 /// </summary>
 /// <param name="fieldName">field name</param>
 /// <param name="value">value</param>
 /// <returns>true for successfully deleted</returns>
 public bool Delete(CTree_expression.CTree_expressionFields fieldName, object value)
 {
     return(_dataObject.DeleteByField(fieldName.ToString(), value));
 }