Question

SQL Server如何知道以这种方式检索这些值？

Key         someMoney
----------- ---------------------
1           5.00
2           5.002
3           5.0001

基本上，我想知道如何知道有多少小数位而没有太大的性能损失。

我想要

Key         someMoney             places
----------- --------------------- ----------
1           5.00                  2
2           5.002                 3
3           5.0001                4

Answer 1

Money有4个小数位....它是一个定点数据类型。

Answer 2

这会产生正确的结果，但我不确定它是否表现得足够好，我没有尝试过除了你列出的例子以外的数据：

;
with money_cte ([Key], [someMoney])
as
(
    select 1, cast(5.00 as money)
    union
    select 2, cast(5.002 as money)
    union
    select 3, cast(5.0001 as money)
)

select [Key], [someMoney], abs(floor(log10([someMoney] - round([someMoney], 0, 1)))) as places
from money_cte 
where [someMoney] - round([someMoney], 0, 1) <> 0

union

select [Key], [someMoney], 2 as places
from money_cte 
where [someMoney] - round([someMoney], 0, 1) = 0

Answer 3

所以这是一个巨大的丑陋黑客，但它会给你你正在寻找的价值......

DECLARE @TestValue MONEY
SET @TestValue = 1.001

DECLARE @TestString VARCHAR(50)
SET @TestString = REPLACE(RTRIM(REPLACE(CONVERT(VARCHAR, CONVERT(DECIMAL(10,4), @TestValue)), '0', ' ')), ' ', '0')

SELECT LEN(@TestString) - CHARINDEX('.', @TestString) AS Places

Answer 4

客户端正在格式化。 SQL Server SSMS或其他。 SQL Server在数据流中返回一个完整的货币值，它需要一个完整的8个字节。（http://msdn.microsoft.com/en-us/library/cc448435.aspx）。如果您将SQL Server转换为varchar，则默认为2个小数位

请注意，Stack Overflow数据浏览器甚至没有显示相同的结果：

http://data.stackexchange.com/stackoverflow/q/111288/

;
with money_cte ([Key], [someMoney])
as
(
    select 1, cast(5.00 as money)
    union
    select 2, cast(5.002 as money)
    union
    select 3, cast(5.0001 as money)
)

select *
    , CONVERT(varchar, someMoney) AS varchar_version
    , CONVERT(varchar, someMoney, 2) AS varchar_version2
FROM money_cte

SQL Server如何知道用于赚钱的精度

4 个答案: