Question

我对sql server有点新，所以希望这不是太复杂的事情。如果我有一个包含大量数据的表格，这些数据显示已完成或不完整的记录......

表1

ID    CATEGORY    COMPLETE
1     reports     yes
2     reports     no
3     processes   no
4     processes   yes
5     reports     no
6     events      yes

...创建一个新字段的最佳方法是什么，以显示每个类别的完整百分比？

表2

ID    CATEGORY    PERCENTAGE
1     events      100%
2     processes   50%
3     reports     33%

任何帮助将不胜感激，谢谢。

Answer 1

group by类别列，并使用条件求和来获取分子中的complete = 'yes'个案例。

select category,
100 * 1.0 * sum(case when complete = 'yes' then 1 else 0 end)/count(*) as pct
from tablename 
group by category

Answer 2

您可以使用窗口函数和const int GWL_STYLE = -16; //No ScrollBar const int LVS_NOSCROLL = 0x2000; private bool noScrollBar = false; public bool NoScrollBar { get { return noScrollBar; } set { noScrollBar = value; int style = (int)NativeMethods.GetWindowLong(Handle, GWL_STYLE); if (noScrollBar) { NativeMethods.SetWindowLong(Handle, GWL_STYLE, style | LVS_NOSCROLL); } else { NativeMethods.SetWindowLong(Handle, GWL_STYLE, style & ~LVS_NOSCROLL); } } }：

PARTITION BY Category

的 LiveDemo

插入第二个表：

SELECT DISTINCT Category, [percentage] = ROUND(100 * SUM(CASE complete WHEN 'yes' THEN 1.0 ELSE 0.0 END) OVER (PARTITION BY Category)/ COUNT(*) OVER (PARTITION BY Category),0) FROM #tab;

的 LiveDemo2

Answer 3

我认为最简单的方法是使用avg()：

select category,
       avg(case when complete = 'yes' then 100.0 else 0 end) as pct
from tablename 
group by category;

如果你想把它作为一个百分比的数字，你需要更多的字符串操作：

select category,
       str(avg(case when complete = 'yes' then 100.0 else 0 end)) + '%' as pct
from tablename 
group by category;

但是，我建议将值保留为数字。

SQL Server完成百分比类别

3 个答案: