我應該使用CTE，子查詢，臨時表還是其他方法？

Question

我一直與SQL幾個月，我無法決定幾件事情對這個特定的任務：

1. 可以在SQL輸出的數據，我需要它的方式嗎？
2. 如果需要，我應該使用哪種方法？

我已經把每個學校按年級劃分了下來，而第二列有每個年級的總入學率。我試圖總結每個年級所有在校學生與下列所需的輸出所有學校：

Grade Total Enrolled 
K  7,871 
1  8,321 
2  8,087 
3  8,164 
4  8,237 
5  8,055 

謝謝您的幫助！

我試過這個使用子查詢，但它顯示了重複在表中的所有記錄每行的總數，而不是隻有一行總計。

子查詢：

SELECT (SELECT SUM(Totalenrollment) FROM Dbo.['2013Cycle_1_Data'] 
    WHERE Grade LIKE '%6%' AND Level = 'MS') AS Grade6 

CTE代碼：

WITH 
    TK AS ( SELECT SUM(Totalenrollment) AS Kindergarten FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%KIND%' AND Level = 'ES') 
, T1 AS ( SELECT SUM(Totalenrollment) AS Grade1  FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%1%' AND Level = 'ES') 
, T2 AS ( SELECT SUM(Totalenrollment) AS Grade2  FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%2%' AND Level = 'ES') 
, T3 AS ( SELECT SUM(Totalenrollment) AS Grade3  FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%3%' AND Level = 'ES') 
, T4 AS ( SELECT SUM(Totalenrollment) AS Grade4  FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%4%' AND Level = 'ES') 
, T5 AS ( SELECT SUM(Totalenrollment) AS Grade5  FROM Dbo.['2013Cycle_1_Data'] WHERE Grade LIKE '%5%' AND Level = 'ES') 

SELECT * FROM TK 
UNION ALL 
SELECT * FROM T1 
UNION ALL 
SELECT * FROM T2 
UNION ALL 
SELECT * FROM T3 
UNION ALL 
SELECT * FROM T4 
UNION ALL 
SELECT * FROM T5 

Answer 1

只需使用CASE語句由年級水平來確定檔次水平，然後組：

select 
    case 
     when Grade LIKE '%KIND%' AND Level = 'ES' then 'K' 
     when Grade LIKE '%1%' AND Level = 'ES' then '1' 
     else 'Other Grades' 
    end as GradeLevel, 
    sum(TotalEnrollment) as Enrolled 
from 
    Dbo.['2013Cycle_1_Data'] 
group by 
    case 
     when Grade LIKE '%KIND%' AND Level = 'ES' then 'K' 
     when Grade LIKE '%1%' AND Level = 'ES' then '1' 
     else 'Other Grades' 
    end