AWS Athena 中整数数组的总和

Question

我有一列包含整数数组，如下所示

{   
    "X":[-11,-11,-11,-17],
    "Y":[184,180,184,184],
    "Z":[144,140,144,142]
}

我将 X、Y 和 Z 映射为列，但我没有通过使用 sum

得到总和

我试过了

SELECT X AS items,
x_item AS (
  SELECT i AS array_items
  FROM "test_database"."quicktest", UNNEST(items) AS t(i)
)
SELECT array_items, sum(val) AS total

&

select sum(X) FROM "test_database"."quicktest"

它给了我 sql 错误和我遗漏的东西！！ 如有任何意见或建议，我们将不胜感激。

Answer 1

例如你可以使用reduce函数：

https://prestodb.io/docs/0.172/functions/array.html

https://prestodb.io/docs/0.172/functions/lambda.html#reduce

示例代码：

SELECT x, reduce(x, 0, (s, x) -> s + x, s -> s) as sum_x,
y, reduce(y, 0, (s, x) -> s + x, s -> s) as sum_y,
z, reduce(z, 0, (s, x) -> s + x, s -> s) as sum_z
FROM example