Question

我有9列的教师表

TeacherID, TeacherName, Reception, Year1, Year2, Year3, Year4, Year5, ALevel

我需要将最小和最大位值（接收 - 年份5）连接到1，然后将其显示在select语句中，使其输出为（在本例中为年份1,2和3）：Y1 - Y3

SELECT 
    TeacherID, TeacherName, 
    Reception + Year1 + Year2 + Year3 + Year4 + Year5 + ALevel as 'KeyStage' 
FROM Teachers

关于如何做到这一点的任何想法？

非常感谢，马特

Answer 1

试试这个; First Case 从Reception 开始， MinYear和 Second Case 从{{1开始对于ALevel。同时为每个案例添加MaxYear，以避免在没有任何案例为1

时获取null

else

Answer 2

SELECT 
    TeacherID,
    TeacherName,
    CASE
        WHEN Reception > 0 THEN 'Re'
        WHEN Year1 > 0 THEN 'Y1'
        WHEN Year2 > 0 THEN 'Y2'
        WHEN Year3 > 0 THEN 'Y3'
        WHEN Year4 > 0 THEN 'Y4'
        WHEN Year5 > 0 THEN 'Y5'
        WHEN ALevel > 0 THEN 'AL'
        ELSE '' END 
    + ' - ' +
    CASE
        WHEN ALevel > 0 THEN 'AL'
        WHEN Year5 > 0 THEN 'Y5'
        WHEN Year4 > 0 THEN 'Y4'
        WHEN Year3 > 0 THEN 'Y3'
        WHEN Year2 > 0 THEN 'Y2'
        WHEN Year1 > 0 THEN 'Y1'
        WHEN Reception > 0 THEN 'Re'
        ELSE '' END AS Range
FROM
    Teachers

Answer 3

我不会。在您的客户端代码（php，c＃whatever）中执行此操作。您的规格也不清楚，如果选中年份1,3和5，而2和4不是？

Answer 4

这应该对你有用，我没有测试过，你可能需要做一些改变。请注意，如果没有检查位，那么您将获得一个空值。我会使用null，因为如果没有检查，那么你没有这个奇怪的短划线，你可以使用isnull将值更改为你想要的没有选择的年份。

SELECT TeacherID, 
   TeacherName,
   case when Reception = 1 then 'R'
        when Year1 = 1 then 'Y1'
        when Year2 = 1 then 'Y2'
        when Year3 = 1 then 'Y3'
        when Year4 = 1 then 'Y4'
        when Year5 = 1 then 'Y5'
        when ALevel = 1 then 'AL'
        else null end + ' - ' + 
   case when Reception = 1 then 'R'
        when Year1 = 1 then 'Y1'
        when Year2 = 1 then 'Y2'
        when Year3 = 1 then 'Y3'
        when Year4 = 1 then 'Y4'
        when Year5 = 1 then 'Y5'
        when ALevel = 1 then 'AL'
        else null end as 'KeyStage' 
FROM Teachers

从几个位变量中选择Min和Max

4 个答案: