问题
I have a view which needs to return type decimal for columns stored as float.
I can cast each column to decimal as follows:
, CAST(Field1 as decimal) Field1
The problem with this approach, is that decimal defaults to 18,0, which automatically rounds the float columns to 0. I would like to keep a precision of up to 12 decimal places.
However, if I do this:
, CAST(Field1 as decimal(12,12)) Field1
I get a runtime error:
"Arithmetic overflow error converting float to data type numeric"
the float column is defined as length: 8 Precision: 53 in the table. I can not modify anything about the table.
What's the proper way to cast it as decimal w/out losing decimal precision?
回答1:
12, 12 means no digits before the decimal separator: 12 digits in total, 12 of them being after the period.
Use a more appropriate range, say:
DECLARE @var FLOAT = 100
SELECT CAST(@var as decimal(20,12))
which gives you 8 digits before the separator, or adjust it as needed.
来源：https://stackoverflow.com/questions/4186789/converting-float-to-decimal-in-sql-server-2008