Question

我分配了一个名为table的表，其中包括两个字段task_idXXXStatus。我想查找完成率，不过这是对状态= complete进行过滤时表中的行数除以表中的总行数* 100.下面是示例表：

Answer 1

这是一个简单的方法：

select avg(case when status = 'Complete' then 100.0 else 0.0 end) as rate
from t;

这使用平均值，这比将完成数求和并除以总数要简单一些。

您实际上也可以将其用join而不是case表达式来表达：

select avg(coalesce(v.val, 0.0)) as rate
from t left join
     (values ('Complete', 100.0)) v(status, val)
     on v.status = t.status

Answer 2

您可以使用条件聚合：

SELECT 100.0*SUM(IIF(Status='Complete',1, 0)/NULLIF(COUNT(*),0) AS ratio
FROM tab

Answer 3

根据条件status = 'Completed'用sum计算行数：

SELECT 
  SUM(CASE status WHEN 'Completed' THEN 1 ELSE 0 END) * 100.0 / COUNT(*) AS percentage
FROM tablename

Answer 4

如果我通过您的查询逐步进行简单说明

            Select * from
            ( (( SELECT COUNT(*) FROM TABLE 
             WHERE STATUS 
          ='Completed` ) /
            (SELECT COUNT(Distinct *) FROM TABLE))*100)

Answer 5

我想知道当同一task_id具有多个status时会产生什么含义？

像 111 ？它同时显示“已完成”和“未完成”。

此表中是否可能需要考虑具有日期和时间值的第三列？

此版本的答案可以处理任何“状态”值...

CREATE table my_table
(
task_Id int NOT NULL,
task_status varchar(50) NOT NULL,
);    

INSERT INTO my_table VALUES(111, 'Not Completed');
INSERT INTO my_table VALUES(129, 'Completed');
INSERT INTO my_table VALUES(111, 'Completed');
INSERT INTO my_table VALUES(135, 'Not Completed');
INSERT INTO my_table VALUES(136, 'Not Completed');
INSERT INTO my_table VALUES(137, 'Not Completed');
INSERT INTO my_table VALUES(119, 'Completed');
INSERT INTO my_table VALUES(112, 'Not Completed');
INSERT INTO my_table VALUES(118, 'Completed');
INSERT INTO my_table VALUES(126, 'Not Completed');
INSERT INTO my_table VALUES(777, 'In Process');
INSERT INTO my_table VALUES(888, 'In Process');
INSERT INTO my_table VALUES(999, 'Waiting for something');


WITH s1 -- JJAUSSI: count the distinct list of task_id values
AS
(
SELECT COUNT(DISTINCT t.task_id) as task_count_total
  FROM my_table t
)
SELECT t.task_status
      ,CAST(COUNT(DISTINCT t.task_id) AS decimal)/CAST(s1.task_count_total as decimal) as task_status_percent_of_total
      ,COUNT(DISTINCT t.task_id) as task_status_count
      ,s1.task_count_total      
  FROM my_table t
  CROSS JOIN s1
 GROUP BY t.task_status
        ,s1.task_count_total
 ORDER BY 1;

我在那里使用了一个简单的通用表表达式。

本文在Common Table Expressions中有更多介绍。

这些是结果...

+----+-----------------------+------------------------------+-------------------+------------------+
|    |      task_status      | task_status_percent_of_total | task_status_count | task_count_total |
+----+-----------------------+------------------------------+-------------------+------------------+
|  1 | Completed             |        0.3333333333333333333 |                 4 |               12 |
|  2 | In Process            |        0.1666666666666666666 |                 2 |               12 |
|  3 | Not Completed         |        0.5000000000000000000 |                 6 |               12 |
|  4 | Waiting for something |        0.0833333333333333333 |                 1 |               12 |
+----+-----------------------+------------------------------+-------------------+------------------+

我使用this tool创建了ASCII表。希望这可以帮助您入门。

如何编写SQL查询以从表中查找完成率

5 个答案: