算术溢出或其他算术异常发生的解决方案？

Question

我正在使用db2，不知道什么版本。尝试对表格进行求和时出现溢出错误。我认为我可以将总和转换为BIGINT，这似乎适用于总数，但我希望得到一个百分比，当我投入BIGINT时，我的数据不准确。如何获得Percent_DeliveredB/A的准确百分比？将分子和分母转换为BIGINT并除以百分数不会给我正确的结果。

这里是我的脚本：

SELECT 
FAT.DIM_BUILDING_ID, 
FAT.BUILDING_NAME, 
SUM(CAST(FAT.AMOUNT AS BIGINT)) AS SALES_SUM, 
SUM(CAST(FAT.ORDERS AS BIGINT)) AS ORDERS_SUM, 
SUM(CAST(FAT.CAPABILITY AS BIGINT)) AS CAPABILITY_SUM, 
SUM(FAT.ORDERS_B)/sum(FAT.Amount) AS Percent_DeliveredB, 
SUM(FAT.ORDERS_A)/sum(FAT.Amount) AS Percent_DeliveredA, 
SUM(CAST(FTS.GROUP_A AS BIGINT)) AS GROUP_A, 
SUM(CAST(FTS.GROUP_B AS BIGINT)) AS GROUP_B, 
SUM(CAST(FTS.GROUP_C AS BIGINT)) AS GROUP_C 

FROM ORDERS AS FAT 
INNER JOIN GROUPS AS FTS ON FAT.DIM_PROJECT_ID = FTS.DIM_PROJECT_ID 
GROUP BY FAT.DIM_BUILDING_ID, FAT.BUILDING_NAME; 

我尝试以下，但它与0回来的百分比。

SUM(CAST(FAT.ORDERS_B AS BIGINT))/sum(CAST(FAT.Amount AS BIGINT)) AS Percent_DeliveredB 

Answer 1

我能够得到正确的结果转换为双倍。

SUM(CAST(FAT.ORDERS_B AS DOUBLE))/sum(CAST(FAT.Amount AS DOUBLE)) AS Percent_DeliveredB, 

Answer 2

这是给你一个正确的结果，小于1的任何值，转换为一个整数（或BIGINT为此事）时将被截断为0，很明显。如果你期待一个分数，使用十进制或浮点数据类型：

cast(SUM(FAT.ORDERS_B) as decimal(10,2))/
cast(sum(FAT.Amount) as decimal(10,2)) AS Percent_DeliveredB 

使用正确的精度满足您的需求，当然。