循環遍歷行並根據表名進行計數

Question

這是我的數據庫表：

Status
------
Active
Active
Inactive
Removed
Removed

我想要的輸出：

Status   |  Total  | Percent
-------------------------------
Active   |    2    |  33.33   
Inactive |    1    |  16.66
Removed  |    3    |  50
Total    |    6    |  100

我嘗試過的：

SELECT
    OrderStatus AS Status,
    COUNT(OrderStatus) AS Total,
    ROUND(((COUNT(OrderStatus ) * 100)/COUNT(*)),2) AS Percent
FROM
    myTable

由於顯而易見的原因，我的查詢無效，任何幫助表示贊賞！

Answer 1

您缺少group by子句，您需要除以記錄的總數，您可以使用子查詢獲得這些記錄：

SELECT
    OrderStatus AS Status,
    COUNT(OrderStatus) AS Total,
    ROUND((COUNT(OrderStatus ) * 100)/(select COUNT(*) from myTable),2) AS [Percent]
FROM
    myTable
Group by OrderStatus

Answer 2

將表中的總記錄分配給變量。 這將防止需要為每條記錄重新計算它。 只有5條記錄的小問題，但如果您將此邏輯應用於具有更多唯一值的更大表，則差異應該變得顯着。

SQL：

declare @TempTable table([OrderStatus] varchar(50))

insert into @TempTable
values
('Active'),
('Active'),
('Inactive'),
('Removed'),
('Removed')

DECLARE @TotalRecords int = (Select Count(*) from @TempTable)

SELECT
    OrderStatus AS Status,
    COUNT(OrderStatus) AS Total,
    ROUND((COUNT(OrderStatus ) * 100)/@TotalRecords,2) AS [Percent]
FROM
    @TempTable
Group by OrderStatus

結果：

(5 row(s) affected)
Status                                             Total       Percent
-------------------------------------------------- ----------- -----------
Active                                             2           40
Inactive                                           1           20
Removed                                            2           40

(3 row(s) affected)