fix issue 1492

[Yang2096]

fix #1492 with the solution given by @small-cat .

SELECT o.item.line_item_id, o.item.quantity FROM short_orders o

Before

(sql_script 
    (unit_statement 
        (data_manipulation_language_statements 
            (select_statement 
                (subquery 
                    (subquery_basic_elements 
                        (query_block SELECT 
                            (selected_element 
                                (select_list_elements 
                                    (regular_id O)
                                    . (expressions     //  all selected_elements were parsed to a single seleced_element
                                        (expression 
                                        (logical_expression 
                                        (unary_logical_expression 
                                        (multiset_expression 
                                        (relational_expression 
                                        (compound_expression 
                                        (concatenation 
                                        (model_expression 
                                        (unary_expression 
                                        (atom 
                                        (general_element 
                                        (general_element_part 
                                            (id_expression (regular_id ITEM)) 
                                            . (id_expression (regular_id LINE_ITEM_ID))
                                        )))))))))))) , 
// the second select_list_element was parsed as a expression
                                        (expression 
                                        (logical_expression 
                                        (unary_logical_expression 
                                        (multiset_expression 
                                        (relational_expression 
                                        (compound_expression 
                                        (concatenation 
                                        (model_expression 
                                        (unary_expression 
                                        (atom 
                                        (general_element 
                                        (general_element_part 
                                            (id_expression (regular_id O)) . 
                                            (id_expression (regular_id ITEM)) . 
                                            (id_expression (regular_id QUANTITY))))))))))))))
                                    )
                                )) 
                            (from_clause FROM 
                                (table_ref_list 
                                (table_ref 
                                (table_ref_aux 
                                (table_ref_aux_internal 
                                (dml_table_expression_clause 
                                (tableview_name 
                                (identifier 
                                (id_expression 
                                    (regular_id SHORT_ORDERS)))))) 
                                (table_alias 
                                (identifier 
                                (id_expression 
                                    (regular_id O)))))))
                            )
                        )
                    )
                )
            )
        )
    ) 
<EOF>
)

After

(sql_script 
    (unit_statement 
        (data_manipulation_language_statements 
            (select_statement 
                (subquery 
                    (subquery_basic_elements 
                        (query_block SELECT 
                            (selected_list 
                                (select_list_elements 
                                    (expression 
                                    (logical_expression 
                                    (unary_logical_expression 
                                    (multiset_expression 
                                    (relational_expression 
                                    (compound_expression 
                                    (concatenation 
                                    (model_expression 
                                    (unary_expression 
                                    (atom 
                                    (general_element 
                                    (general_element_part 
                                        (id_expression (regular_id O)) . 
                                        (id_expression (regular_id ITEM)) . 
                                        (id_expression (regular_id LINE_ITEM_ID))
                                    ))))))))))))) , 

                                (selected_list_element 
                                    (expression 
                                    (logical_expression 
                                    (unary_logical_expression 
                                    (multiset_expression 
                                    (relational_expression 
                                    (compound_expression 
                                    (concatenation 
                                    (model_expression 
                                    (unary_expression 
                                    (atom 
                                    (general_element 
                                    (general_element_part 
                                        (id_expression (regular_id O)) . 
                                        (id_expression (regular_id ITEM)) . 
                                        (id_expression (regular_id QUANTITY))
                                    )))))))))))))) 
                            (from_clause FROM 
                                (table_ref_list 
                                    (table_ref 
                                    (table_ref_aux 
                                    (table_ref_aux_internal 
                                    (dml_table_expression_clause 
                                    (tableview_name 
                                    (identifier 
                                    (id_expression 
                                        (regular_id SHORT_ORDERS)))))) 
                                    (table_alias 
                                        (identifier (id_expression (regular_id O)))
                                    ))))
                            )
                        )
                    )
                )
            )
        )
    ) 
<EOF>
)

[Yang2096]

The old grammar has another mistake, you can write SQL like select table.* as ALL from table;, which is impossible in reality.