Question

我需要显示＆＃34;预定与实际＆＃34;报告显示MySQL数据库中两个表之间的差异，该表存放学校。

我有两张名为Booking and Attendance的表。

表中存储的数据如下：

预订

Id Student   Date     IsAbsent
1  John      20160216    1 //NO
2  Bob       20160217    1 //NO
3  Zara      20160218    1 //NO

考勤

Id Student    Date     IsAbsent
1  John       20160216    0 //YES
2  Bob        20160217    0 //YES
3  Mary       20160217    1 //NO

基本上我想将输出显示为

**Id | Student | Day_1 | Day_2  |  Day_3**
 ==== ========= ======  =======  ======
   1 | John    |ABSENT | NULL   | NULL 
   2 | Bob     |NULL   |ABSENT  | NULL
   3 | Mary    |NULL   |NEW     | NULL
   4 | Zara    |DELETED|NULL    | NULL

缺席预订表中的约翰被标记为1（错误）但在考勤表中他被标记为0（是）所以我想显示为＆＃39;缺席＆＃ 39;

新玛丽只在考勤表中有一个条目，但不是在预订表中。

已删除 Zara最初已预订，位于预订表中，但不在考勤表中。

我创建了SQL Fiddle架构和我正在使用的查询，但它总是返回null。

我的SQL查询如下所示..

 SELECT * FROM 
((SELECT
  a.Student as student,
   MAX( case
       when a.DropDate='20160216' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160216')=0 && (select count(*) from staging where DropDate='20160216')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160216')>0 && (select count(*) from staging where DropDate='20160216')=0 then 'New Booking' 
       else ' ' end ) as 'day_1',
  MAX( case 
       when a.DropDate='20160217' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160217')=0 && (select count(*) from staging where DropDate='20160217')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160217')>0 && (select count(*) from staging where DropDate='20160217')=0 then 'New Booking' 
       else ' '  end ) as 'day_2',
  MAX( case 
       when a.DropDate='20160218' && a.IsAbsent=0 && s.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160218')=0 && (select count(*) from staging where DropDate='20160218')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160218')>0 && (select count(*) from staging where DropDate='20160218')=0 then 'DELETED Booking' 
       else ' '  end ) as 'day_3'
FROM Attendance a LEFT JOIN Booking s on a.Student=s.Student
WHERE a.DropDate IN ('20160216','20160217','20160218')
   AND  NOT EXISTS 
      ( SELECT 1
        FROM Booking AS p
        WHERE p.Student = a.Student
          AND p.IsAbsent = a.IsAbsent
          AND p.DropDate = a.DropDate
      )
)
UNION 
(SELECT
  t.Student as student,
  MAX( case
       when t.DropDate='20160216' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160216')=0 && (select count(*) from staging where DropDate='20160216')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160216')>0 && (select count(*) from staging where DropDate='20160216')=0 then 'New Booking' 
       else ' ' end ) as 'day_1',
  MAX( case 
       when a.DropDate='20160217' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160217')=0 && (select count(*) from staging where DropDate='20160217')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160217')>0 && (select count(*) from staging where DropDate='20160217')=0 then 'New Booking' 
       else ' '  end ) as 'day_2',
  MAX( case 
       when a.DropDate='20160218' && a.IsAbsent=0 && t.IsAbsent=1 then 'Absent'
       when (select count(*) from attendance where DropDate='20160218')=0 && (select count(*) from staging where DropDate='20160218')>0 then 'DELETED Booking'
       when (select count(*) from attendance where DropDate='20160218')>0 && (select count(*) from staging where DropDate='20160218')=0 then 'DELETED Booking' 
       else ' '  end ) as 'day_3'
FROM Booking t LEFT JOIN attendance a on t.Student=a.Student
WHERE t.DropDate IN ('20160216','20160217','20160218')
  AND  NOT EXISTS 
      ( SELECT 1
        FROM Attendance AS u
        WHERE u.Student = t.Student
          AND u.IsAbsent = t.IsAbsent
          AND u.DropDate = t.DropDate
      )
)) tbl
ORDER BY  student

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Answer 1

我不确定你可以在MySQL查询中输出内联布局，除非你做了一个程序...... 我不知道这对你来说是否合适，因为它的布局略有不同，但它有效：

(select s.Student,
       s.ClassRoom,
       s.DropDate,
       if(s.IsAbsent=1&&a.IsAbsent=0,'ABSENT','PRESENT')
from Staging s inner join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate)
UNION ALL
(Select s.Student,
       s.ClassRoom,
       s.DropDate,
       'DELETED'
from Staging s left join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate
where a.Student is null)
UNION ALL
(Select a.Student,
       a.ClassRoom,
       a.DropDate,
       'NEW'
from Staging s right join Attendance a on a.Student = s.Student and a.ClassRoom = s.ClassRoom and a.DropDate = s.DropDate
where s.Student is null)
order by Student, DropDate;

MySQL获取不同的记录至少有两个表

1 个答案: