converting varchar to number and sum gives error:

Question

我试图通过将其转换为数字来对此列求和，但这些值也有逗号，这是我查询中的错误来源：

SELECT date_trunc('day', to_date("date" , 'mm-dd-yyyy')) as day, 
"from merch", 
sum(CAST("amount " AS numeric)) as amount 
FROM tb 
GROUP BY 1,2 
ORDER BY 1,2;

我正在尝试获取每天每个“来自商品”的金额总和。

我得到的错误是：无效数字，值“,”，位置 1，类型：十进制

Answer 1

demo

使用replace(string,FromValue,ToValue)

注意：这假设您的金额为###,###.00 格式。如果不是，你可以 return 错误数据。

with tb AS 
(SELECT '1,000.01' as "amount", '01-01-2022' as "date",'z' as "from merch" UNION ALL
SELECT '10,000.02' as "amount", '01-01-2022' as "date",'z' as "from merch" UNION ALL
SELECT '100,000.02' as "amount", '02-01-2022' as "date",'y' as "from merch")

SELECT date_trunc('day', to_date("date" , 'mm-dd-yyyy')) as day, 
"from merch", 
sum(CAST(replace("amount",',','') AS numeric)) as amount 
FROM tb 
GROUP BY 1,2 
ORDER BY 1,2;

Demo 2 with decimal

sum(CAST(replace("amount",',','') AS decimal(10,2))) as amount

假设您已正确识别问题。

我（不是最近）在评论中发现了幽默的交流：

如果您需要对其进行数学运算，请将其存储为数字
如果您永远不会对其进行数学运算，请将其存储为字符串
如果两者都需要，则需要两列
日期除外...将日期存储为日期期间并在其上使用日期函数...不是字符串 {shudder} 函数！
和 AutoIncrements 可以是数字（尽管我们永远不应该对它们进行数学运算）

@xQbert——此后将被称为“xQbert 的剃刀”

converting varchar to number and sum gives error:

converting varchar to number and sum gives error:

sql

postgresql

casting

group-by