Convert to valid decimal data type

问题

I have a column [Cash] nvarchar(50) that has data that will later be converted to decimal(9,3) during an import process,some of the data is consistent with normal looking numeric values such as 134.630,-80.662 and 324.372. Occasionally I have data with multiple dots for the numeric values such as 1.324.372 and -2.134.630. Is there a way of removing this extra dot.

回答1:

declare @yourtable table(cash varchar(20))
insert @yourtable values('1.324.372')
insert @yourtable values('-2.134.630')
insert @yourtable values('1.234.567.89')

Old Code:

select reverse(replace(replace(stuff(reverse(cash), charindex(
    '.', reverse(cash)), 1, ','), '.', ''), ',', '.')) 
from @yourtable

Slightly upgraded code(result is the same):

select reverse(stuff(reverse(replace(cash, '.', '')), 
    charindex('.', reverse(cash)), 1, '.'))
from @yourtable

Result:

1324.372
-2134.630
1234567.89

回答2:

You could;

select case when len(cash) - len(replace(cash, '.', '')) > 1 then
    reverse(stuff(reverse(cash), charindex('.', reverse(cash)), 1, ''))
else    
    cash
end
from T

回答3:

Create a view that includes a calculated field with the proper value.

That way you can still see the varchar value and the corresponding decimal value.

Something like this:

select [Cash], cast(replace([Cash],'.','') as decimal) as [CashDecimal]
from ....

来源：https://stackoverflow.com/questions/7711358/convert-to-valid-decimal-data-type