使用窗口函数运行 Total UDF（用户定义函数）会抛出“无法强制输出值”

Question

输入数据集：

日期	身份证	数量	想要的
2020-01-01	1	8	8
2020-01-02	1	11.5	19.5
2020-01-03	1	-20	0
2020-01-04	1	10	10
2020-01-05	1	-5	5
2020-01-06	2	-9	0
2020-01-07	2	26	26
2020-01-08	2	5	31
2020-01-09	2	-23	8
2020-01-10	2	-10.5	0
2020-01-11	2	5	5

我正在尝试创建一个自定义运行总计，每当运行总计低于 0 时，该总计都会重置为 0。

我的代码

CREATE TEMP FUNCTION conditional_sum(X ARRAY<FLOAT64>)
RETURNS FLOAT64
LANGUAGE js as r"""
    if (!('sum' in this)) this.sum =0
    return this.sum = (X + this.sum) <0 ? 0 : this.sum + X
""";
select *,conditional_sum(array_agg(number) over (partition by ID order by Date)) as run_sum from tbl

我得到的错误是

 Failed to coerce output value "11.5,-20" to type FLOAT64. Bad double value

我从运行正数和负数的总和，其中总和不能低于零借用了这段代码，并且在没有窗口函数和arrary_agg的情况下它也能很好地工作。但我需要窗口函数，因为我需要将条件总和应用于 Bigquery SQL 中的多个 ID

其他 udf 错误不处理窗口函数

Answer 1

请在 JavaScript 代码中添加 for 循环。仅生成当前行的数组。

CREATE TEMP FUNCTION conditional_sum(X ARRAY<FLOAT64>)
RETURNS FLOAT64
LANGUAGE js as r"""
var cur=0;
var out=[];
  for(let x of X){
    cur+=x*1;
    if(cur<0) cur=0;
    //out.push(cur)
  }
  return cur;
  //  return out;
""";
With tbl as (
SELECT '2020-01-01' AS Date, 1 AS ID, 8 AS Number, 8 AS Desired
UNION ALL SELECT '2020-01-02', 1, 11.5, 19.5
UNION ALL SELECT '2020-01-03', 1, -20, 0
UNION ALL SELECT '2020-01-04', 1, 10, 10
UNION ALL SELECT '2020-01-05', 1, -5, 5
UNION ALL SELECT '2020-01-06', 2, -9, 0
UNION ALL SELECT '2020-01-07', 2, 26, 26
UNION ALL SELECT '2020-01-08', 2, 5, 31
UNION ALL SELECT '2020-01-09', 2, -23, 8
UNION ALL SELECT '2020-01-10', 2, -10.5, 0
UNION ALL SELECT '2020-01-11', 2, 5, 5
)

select *,conditional_sum([1.1,2,1]),
string_agg(cast(number as float64) || '' ) over win1,
conditional_sum(array_agg(cast(number as float64)) over win1 ) as run_sum 
from tbl
window win1 as (partition by ID order by Date rows between unbounded preceding and current row)