Question

我有两个包含类似数据的数据库表 - 一个是流程完成的工作量，另一个是该流程产生的错误数量。

我想显示正确的第一次工作的百分比。

我按进程计算项目数的查询是：

SELECT Counter.Process, count( Counter.Process ) AS count
                            FROM Counter WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
                            GROUP BY Counter.Process
                            ORDER BY count DESC

上面给出了一个类似于：

的列表

Process    | count
-------------------
Process A  | 40
Process B  | 32
Process C  | 102
Process D  | 23

我有第二个表格，其中包含相同的字段，用于记录错误，称为“错误”。

通过使用相同的查询（但显然更改了表名），我可以得到一个进程和错误列表。

我想要做的是创建一个PHP网页，显示每个进程的错误百分比。

我的问题是如果我单独创建两个查询，当我使用PHP Where循环遍历它们时我不知道如何使计算显示百分比。

我尝试在两个SQL查询之间使用UNION，但我不能让它显示针对该进程的两个不同的计数读数。

理想情况下，我想要一种显示数据的方法：

Process   | Counter.count | Errors.count
Process A     40              2
Process B     32              0
Process C     102             18
Process D     23              8

我非常感谢有关如何实现这一目标的任何建议/建议 - 如果您需要有关我的数据库表的更多信息，请告诉我

感谢您阅读

取值

Answer 1

我没有运行它所以可能会有错误。你可以做两个选择，然后加入结果：

select s.process, s.success_count, e.error_count
from 
(SELECT Counter.Process as process, count( Counter.Process ) AS success_count
 FROM Counter
 WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
 GROUP BY Counter.Process
) s left join
(SELECT Errors.Process, count( Errors.Process ) AS error_count
      FROM Errors
      WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
      GROUP BY Errors.Process 
) e
on (s.Process = e.process)

Answer 2

我个人更喜欢通过PHP运行这样的情况，因为它让我更加困惑，所以我会解释我认为我会用PHP做什么（我说'想'因为我可能不知道你的数据库结构或系统否则会使我的规格）：

$rows = array();
$res = mysql_query('SELECT Counter.Process, count( Counter.Process ) AS count
                        FROM Counter WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
                        GROUP BY Counter.Process
                        ORDER BY count DESC');
while ($arr = mysql_fetch_assoc($res))
{
    $rows[] = $arr;
}

$res2 = mysql_query('SELECT Errors.Process, count( Errors.Process ) AS count
                        FROM Counter WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
                        GROUP BY Errors.Process
                        ORDER BY count DESC');
while ($arr2 = mysql_fetch_assoc($res2)
{
    for ($i=0; $i<count($rows); $i++)
    {
        if ($arr2["Process"] == $data[$i]["process"])
        {
            break;
        }
        //Do your functions with $arr and $data[$i] at this point...
    }
}

Answer 3

没有子查询这样做应该很简单：

SELECT 
    Counter.Process
    , COUNT(Counter.Process) AS ProcessCount
    , COUNT(Errors.Process) AS ProcessErrors
FROM
    Counter
    LEFT JOIN
    Errors
    ON Counter.Process = Errors.Process
WHERE
    Counter.TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59'
GROUP BY
    Counter.Process

您可以对这两个查询进行说明，看看哪种查询最适合您的数据。

-edit：我已将其更改为LEFT JOIN，因此如果进程没有错误，您不会错过任何行。

Answer 4

您可以使用子查询：

SELECT Counter.Process, count( Counter.Process ) AS Count,
      (SELECT count(Errors.Process) 
         FROM Errors
        WHERE Process=Counter.Process 
          AND (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')) AS Errors
                            FROM Counter WHERE (TIME BETWEEN '2012-07-01 00:00:00' AND '2012-07-06 23:59:59')
                            GROUP BY Counter.Process
                            ORDER BY count DESC

此致尼尔。

从mySQL查询中收集两个单独的列结果

4 个答案: