UNPIVOT - Amazon OpenSearch Service

UNPIVOT

Note

To see which AWS data source integrations support this SQL command, see Supported OpenSearch SQL commands and functions.

The UNPIVOT clause transforms multiple columns into multiple rows used in SELECT clause. The UNPIVOT clause can be specified after the table name or subquery.

Syntax 

UNPIVOT [ { INCLUDE | EXCLUDE } NULLS ] (
    { single_value_column_unpivot | multi_value_column_unpivot }
) [[AS] alias]

single_value_column_unpivot:
    values_column
    FOR name_column
    IN (unpivot_column [[AS] alias] [, ...])

multi_value_column_unpivot:
    (values_column [, ...])
    FOR name_column
    IN ((unpivot_column [, ...]) [[AS] alias] [, ...])

Parameters

  • unpivot_column

    Contains columns in the FROM clause, which specifies the columns we want to unpivot.

  • name_column

    The name for the column that holds the names of the unpivoted columns.

  • values_column

    The name for the column that holds the values of the unpivoted columns.

Examples

CREATE TABLE sales_quarterly (year INT, q1 INT, q2 INT, q3 INT, q4 INT);
INSERT INTO sales_quarterly VALUES
(2020, null, 1000, 2000, 2500),
(2021, 2250, 3200, 4200, 5900),
(2022, 4200, 3100, null, null);
-- column names are used as unpivot columns
SELECT * FROM sales_quarterly
UNPIVOT (
sales FOR quarter IN (q1, q2, q3, q4)
);
+------+---------+-------+
| year | quarter | sales |
+------+---------+-------+
| 2020 | q2      | 1000  |
| 2020 | q3      | 2000  |
| 2020 | q4      | 2500  |
| 2021 | q1      | 2250  |
| 2021 | q2      | 3200  |
| 2021 | q3      | 4200  |
| 2021 | q4      | 5900  |
| 2022 | q1      | 4200  |
| 2022 | q2      | 3100  |
+------+---------+-------+
-- NULL values are excluded by default, they can be included
-- unpivot columns can be alias
-- unpivot result can be referenced via its alias
SELECT up.* FROM sales_quarterly
UNPIVOT INCLUDE NULLS (
sales FOR quarter IN (q1 AS Q1, q2 AS Q2, q3 AS Q3, q4 AS Q4)
) AS up;
+------+---------+-------+
| year | quarter | sales |
+------+---------+-------+
| 2020 | Q1      | NULL  |
| 2020 | Q2      | 1000  |
| 2020 | Q3      | 2000  |
| 2020 | Q4      | 2500  |
| 2021 | Q1      | 2250  |
| 2021 | Q2      | 3200  |
| 2021 | Q3      | 4200  |
| 2021 | Q4      | 5900  |
| 2022 | Q1      | 4200  |
| 2022 | Q2      | 3100  |
| 2022 | Q3      | NULL  |
| 2022 | Q4      | NULL  |
+------+---------+-------+
-- multiple value columns can be unpivoted per row
SELECT * FROM sales_quarterly
UNPIVOT EXCLUDE NULLS (
(first_quarter, second_quarter)
FOR half_of_the_year IN (
(q1, q2) AS H1,
(q3, q4) AS H2
)
);
+------+------------------+---------------+----------------+
|  id  | half_of_the_year | first_quarter | second_quarter |
+------+------------------+---------------+----------------+
| 2020 | H1               | NULL          | 1000           |
| 2020 | H2               | 2000          | 2500           |
| 2021 | H1               | 2250          | 3200           |
| 2021 | H2               | 4200          | 5900           |
| 2022 | H1               | 4200          | 3100           |
+------+------------------+---------------+----------------+