使用存储过程重新组织数据列雪花

Question

Using stored procdeure in Snowflake I am trying to change the columns order for a part of the data table.

Here is my table

column1 column2 column3 column4    column5
---------------------------------------------
Year   Country  Name    City
2020    US      Briand   NY
2021    US      John     LA
2021    UK      Mark     London

City   Name    Year      Country      Age
Paris  Jacques  2017      FR          55
Madrid Juan     2015      ES          25
Dublin Steven   2018      IE          37

So there is 5 differents structures in the same table. All 5 structures doesn't have the same number of columns but the column name can be match and missing column can be fill with null values. Moreover there is a blank row between each different data structure. The output should be:

Year      Country     City     Name          Age
-------------------------------------------------
2020        US        NY        Briand       Null
2021        US        LA        John         Null
2021        UK        London    Mark         Null
2017        FR        Paris     Jacques      55
2015        ES        Madrid    Juan         25
2018        IE        Dublin    Steven       37

So I thought that the only way is to do a stored procedure but I have no idea how it works and if it is possible to resolve my problem this way.

CREATE OR REPLACE PROCEDURE proc_columns_matching()
returns string
language javascript
as
$$
var sql = "select * from countries_pp";
var statement1 = snowflake.createStatement( {sqlText: pp} );
var result_set1 = statement1.execute();

while(result_set1.next() != ''){
var column1= result_set1.getColumnValue(1)
}

return column1;
$$
;

CALL proc_smart_impulse();

So I tried to identify the blank cell to split the table but I am stuck here.

Answer 1

I believe you cannot re-order columns using ALTER commands and the recommended solution is to use a view. For your case it would probably require using UNION to cater for the different structures