BigQuery:如何获取列中特定字段的值?

一种方法是采用枢轴方法,如下所示:

SELECT
    MAX(CASE WHEN Row = 2 THEN S1 END) +
    MAX(CASE WHEN Row = 3 THEN S2 END) +
    MAX(CASE WHEN Row = 1 THEN S3 END) AS the_sum
FROM yourTable;

如果你真的没有 Row

WITH cte AS (
    SELECT *,
        ROW_NUMBER() OVER (ORDER BY S1) Row
    FROM yourTable
)

然后,使用上面我给出的第一个查询,但是 cte 作为桌子,而不是 yourTable

下面是SQL Server中的一个演示,它至少显示了基本逻辑的工作原理:

Demo

select sum(case when row = 1 then s3
                when row = 2 then s1
                when row = 3 then s2
           end)
from t;

我不认为你能比没有 group by