在 SQL Server 2008 中将浮点数转换为十进制数
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Converting float to decimal in SQL Server 2008
提问by Sonic Soul
I have a view which needs to return type decimal for columns stored as float.
我有一个视图需要为存储为浮点数的列返回十进制类型。
I can cast each column to decimal as follows:
我可以将每一列转换为十进制，如下所示：
, 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.
这种方法的问题是小数默认为 18,0，它会自动将浮点列四舍五入为 0。我想保持最多 12 位小数的精度。
However, if I do this:
但是，如果我这样做：
, CAST(Field1 as decimal(12,12)) Field1
I get a runtime error:
我收到一个运行时错误：
"Arithmetic overflow error converting float to data type numeric"
the float column is defined as length: 8 Precision: 53in the table. I can not modify anything about the table.
浮点列定义为长度：8 精度：表中的53。我无法修改有关表格的任何内容。
What's the proper way to cast it as decimal w/out losing decimal precision?
将其转换为十进制而不丢失小数精度的正确方法是什么？
回答by Quassnoi
12, 12means no digits before the decimal separator: 12digits in total, 12of them being after the period.
12, 12表示小数点分隔符之前没有数字：12总共数字，12其中在句点之后。
Use a more appropriate range, say:
使用更合适的范围，例如：
DECLARE @var FLOAT = 100
SELECT CAST(@var as decimal(20,12))
which gives you 8digits before the separator, or adjust it as needed.
它8在分隔符之前为您提供数字，或根据需要进行调整。
