Question

我正在尝试运行此查询，但似乎在进行数学计算后没有正确格式化数字。比例应为2，但不会显示。

SELECT 30 / 60 as Diff FROM Table

返回0

SELECT Convert( Numeric(8,2), 30 / 60 ) as Diff FROM Table

返回0.00

如何根据需要返回0.50？

Answer 1

您可以尝试以下方法，但实现目标的方法很少。使用变量，或仅对字段本身执行CAST，CONVERT。

 SELECT (CAST(30 AS DECIMAL(8,2)) / CAST(60 AS DECIMAL(8,2))) as Diff FROM Table

 SELECT (CAST(30/60) AS DECIMAL(8,2)) as Diff FROM Table

 SELECT (30/60.0) as Diff FROM Table;

 SELECT CONVERT(DECIMAL(8,2), 30/60.0) as Diff FROM Table

请查看此MSDN article for further reference：

Answer 2

在进行除法之前转换为数字或除实数而不是整数。进行整数运算时，会丢弃任何小数。删除分数后转换对你没有任何好处。

SELECT CONVERT(NUMERIC(8,2),30.0/60.0) AS DIFF FROM TABLE

或选择列而不是使用数字

SELECT CONVERT(NUMERIC(8,2),columnA)/CONVERT(NUMERIC(8,2),columnB) AS DIFF FROM TABLE

（转换两者只是为了确保按照我们想要的规则进行划分）

使用Select语句中的Scale返回分割数字的结果

2 个答案: