Question

我查询了一个放置应用程序跟踪系统，该系统显示了每个学习课程的学生放置和未放置的数量。即使查询返回了所需的结果，我仍在努力创建一个APEX Stacked Bar Chart。

查询：

 SELECT programme_name,
           SUM(CASE WHEN (cv_approval_date IS NOT NULL AND application_status_id <> 7) OR
                         application_status_id  IS NULL
                    THEN 1 ELSE 0 END) as Unplaced,
           SUM(CASE WHEN (cv_approval_date IS NOT NULL AND application_status_id <> 7) OR
                         application_status_id  IS NULL
                    THEN 0 ELSE 1 END) as Placed
    FROM programme LEFT JOIN
         student USING (programme_id) LEFT JOIN
         application USING (student_id)
    GROUP BY programme_name;

输出：

    PROGRAMME_NAME                                | PLACED   | UNPLACED
    BSc (Hons) Computer Science                   | 2        | 2 
    BSc (Hons) Computing and Games Development    | 1        | 0 
    BSc (Hons) Web Applications Development       | 0        | 1 
    BSc (Hons) Marine Biology and Coastal Ecology | 1        | 0

该图应该看起来与此类似 - x轴为Program，y轴为放置的学生数，未放置：

http://ruepprich.files.wordpress.com/2011/03/stacked_bar.png?w=550&h=386

我该怎么做呢？任何帮助将不胜感激！

Answer 1

在Apex中创建图表时，您可以点击＆＃34; 图表查询示例＆＃34;对于一些可以使用该图表类型的示例查询。

对于堆积条形图，给出以下示例：

SELECT NULL LINK,
       ENAME LABEL,
       SAL "Salary",
       COMM "Commission"
FROM   EMP
ORDER  BY ENAME

在您的情况下，我认为您希望您的查询提供以下格式：

SELECT NULL LINK,
       programme_name AS LABEL,
       SUM(...) AS "Unplaced",
       SUM(...) AS "Placed"
FROM ...

修改SELECT查询以创建堆积条形图

1 个答案: