Question

我有学生桌和学生课程表。我正在计算学生完成认证课程的百分比。而不是显示我要求显示如下状态的百分比：

Percent Complete = 0; Training Status would be Assigned; Certification
Status-N/A Percent Complete = 33;Training Status would be In-Progress;
Certification Status-Pending Percent Complete = 66;Training Status
would be Complete; Certification Status-In-Progress

如何计算百分比并显示上述情况而不是百分比？

SELECT CONCAT(Student.LastName,', ', Student.FirstName) AS "FULL NAME",        
    studentcourse.CourseID as "COURSE", 
    studentcourse.Status AS "TRAINING STATUS", studentcourse.PercentComplete,
    studentcourse.status as 'CERTIFICATION STATUS' 
FROM studentcourse, student, Course
where Student.OrgID='DECC'
    AND student.studentID=studentcourse.StudentID
    AND Student.IsActiveFlag='1'
    AND Course.CourseID=StudentCourse.CourseID

示例数据：正在移除百分比列。

FULL NAME         COURSE                 TRAINING STATUS  %Complete CERT STATUS
Adkins, Willa         DECC_PER              not attempted   0   not attempted
Adkins, Willa         LMS_Training_DECC     not attempted   0   not attempted
Akers, Dianne         DECC_PER              not attempted   0   not attempted
Akers, Dianne         LMS_Training_DECC     not attempted   0   not attempted
Alexander, Richard    DECC_PER              not attempted   0   not attempted
Alexander, Richard    LMS_Training_DECC     not attempted   0   not attempted
Altamirando, Ardella  8570_Pending_CE_NE        completed   100 completed
Altamirando, Ardella  8570_Pending_IA           completed   100 completed

尝试使用CASE但遇到语法错误。

Answer 1

此查询假定百分比级别如下：

0％：培训状态Assigned;证书状态N/A
＆gt; 0％且最高33％：培训状态In-Progress;证书状态Pending
＆gt; 33％且最高66％：培训状态Complete;证书状态In-Progress
＆gt; 66％：???

如果这个假设错误，您需要调整以下CASE语句中的数字。

SELECT
  CONCAT(Student.LastName,', ', Student.FirstName) AS "FULL NAME",        
  studentcourse.CourseID as "COURSE", 
  studentcourse.PercentComplete,
  CASE
    WHEN studentcourse.PercentComplete = 0 THEN 'Assigned'
    WHEN studentcourse.PercentComplete <= 33 THEN 'In-Progress'
    WHEN studentcourse.PercentComplete <= 66 THEN 'Complete'
    ELSE 'whatever comes next'
    END AS "TRAINING STATUS",
  CASE
    WHEN studentcourse.PercentComplete = 0 THEN 'N/A'
    WHEN studentcourse.PercentComplete <= 33 THEN 'Pending'
    WHEN studentcourse.PercentComplete <= 66 THEN 'In-Progress'
    ELSE 'whatever comes next'
    END AS "CERTIFICATION STATUS"
FROM studentcourse, student, Course
WHERE Student.OrgID='DECC'
  AND student.studentID=studentcourse.StudentID
  AND Student.IsActiveFlag='1'
  AND Course.CourseID=StudentCourse.CourseID

最后一点说明：较新的ANSI连接可以通过将WHERE逻辑与JOIN逻辑分开来使查询更容易编写和读取：

SELECT
  . . . same as above
FROM studentcourse
INNER JOIN student ON studentcourse.StudentID = student.studentID
INNER JOIN Course ON StudentCourse.CourseID = Course.CourseID
WHERE Student.OrgID='DECC'
  AND Student.IsActiveFlag='1'

MySql查询 - 显示状态

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