public void Add(string fieldName, DbSearchOperation op, object value)
 {
     if (!string.IsNullOrEmpty(fieldName))
     {
         DbSearchConditionInfo info = new DbSearchConditionInfo();
         info.Field           = fieldName;
         info.FieldData       = value;
         info.SearchOperation = op;
         Conditions.Add(info);
     }
 }
        public void Add(Expression <Func <T, object> > expr, DbSearchOperation op, object value)
        {
            string fieldName = expr.GetPropertyName <T>();

            Add(fieldName, op, value);
        }