在SQLite中计算百分比

Question

查询:

select
(
SELECT     COUNT(*)
FROM         Sending s
WHERE     (ConfID = 1) AND (Status = 1)
)
/
(
 (
 SELECT     COUNT(*)
 FROM         Numbers
 WHERE     (ConfID = 1)
 )
 /
 100
)

我想计算百分比。例如，if query

SELECT     COUNT(*)
     FROM         Numbers
     WHERE     (ConfID = 1)

给出100和另一个

 SELECT     COUNT(*)
    FROM         Sending s
    WHERE     (ConfID = 1) AND (Status = 1)

results 50结果查询应该返回50，这意味着50%。但是第一次查询结果为2，第二次查询返回10000，结果查询返回0。我想我应该定义返回浮点数之类的。

谢谢!

Answer 1

试着用100.0代替100。这将强制转换为浮点数据类型:

select
(
SELECT     COUNT(*)
FROM         Sending s
WHERE     (ConfID = 1) AND (Status = 1)
)
/
(
 (
 SELECT     COUNT(*)
 FROM         Numbers
 WHERE     (ConfID = 1)
 )
 /
 100.0
)

Answer 2

尝试:

SELECT SUM(CASE status WHEN 1 THEN 100 ELSE 0 END) / COUNT(*)
  FROM numbers
 WHERE confid = 1