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sqlsql-serverpivotunpivotpartition-by

SQL Server - Pivot Convert rows to columns (with additional row data)


Can someone help me with this SQL?

I am looking to pivot multiple rows into columns by: id, type, color, date

Challenge: I have multiple columns I want to preserve/be shown on the pivoted table.

id | type   | color  | date      | country_code | cost
---+--------+--------+-----------+--------------+-------
1  | report | red    | 2020-09-01| US           | 1
1  | report | red    | 2020-09-01| EU           | 2
1  | report | red    | 2020-09-01| RU           | 3
1  | report | red    | 2020-09-01| AP           | 4
1  | report | blue   | 2020-09-02| US           | 5   
1  | report | blue   | 2020-09-02| EU           | 6
1  | report | blue   | 2020-09-02| RU           | 7
1  | report | blue   | 2020-09-02| AP           | 8
2  | report | green  | 2020-09-02| US           | 9
2  | report | green  | 2020-09-02| EU           | 10
2  | report | green  | 2020-09-02| RU           | 11
2  | report | green  | 2020-09-02| AP           | 12
2  | report | blue   | 2020-09-03| US           | 13
2  | report | blue   | 2020-09-03| EU           | 14
2  | report | blue   | 2020-09-03| RU           | 15
2  | report | blue   | 2020-09-03| AP           | 16

Desired output:

id | type   | color | date       | US | EU | RU | AP
---+--------+-------+------------+----+----+----+----
1  | report | red   | 2020-09-01 | 1  | 2  | 3  | 4
1  | report | blue  | 2020-09-02 | 5  | 6  | 7  | 8
2  | report | green | 2020-09-02 | 9  | 10 | 11 | 12
2  | report | blue  | 2020-09-03 | 13 | 14 | 15 | 16

Known information:

  • there are only 4 country codes.
  • the color value will be same per: id, type, date.

Not sure what is the most cleanest/best way to write this SQL.

I have tried to use

ROW_NUMBER() OVER(PARTITION BY xxx ORDER BY yyy)

and PIVOT but couldn't get the results I was looking for


Solution

  • I think conditional aggregation does what you want:

    select id, type, color, date,
           max(case when country_code = 'US' then cost end) as us,
           max(case when country_code = 'EU' then cost end) as eu,
           max(case when country_code = 'RU' then cost end) as ru,
           max(case when country_code = 'AP' then cost end) as AP
    from t
    group by id, type, color, date;