我怀疑这与我在 SELECT 语句中有 case 语句,然后我试图对此执行 GROUP BY 和 ORDER BY 语句这一事实有关。
我有一个基于两个表之间连接的结果集。一个是 ks2en、ks2ma 和 Ks2av 列的学生表,其值为 2c、2b、2a、3c、3b 等,第二个是每个学生的结果表,例如 A+、A、A-、B+ 等。 ks2en、ks2ma 和 Ks2av 列被分组并将结果求和,从而给出了一个总计网格,其级别在左侧,结果在顶部。然而,Ks2en、Ks2ma 和 Ks2av 三种类型的级别应该根据特定主题带来结果:
Ks2en - English Result
Ks2ma - Maths Result
Ks2av - Any other subject Result
如果 ks2en、ks2ma 或 ks2av 列中没有值,我希望 group by 显示为“No KS2”。
我在底部的代码非常适用于针对 Ks2en 的英语,但我正在努力制定逻辑以根据主题是英语、数学还是其他任何内容来更改结果。
主题通过名为@SubjectName 的变量填充。
下面是我希望我的 sql 执行的伪代码:
If @SubjectName = 'English' then
If ks2en ='' then
display 'No KS2'
else Ks2en
endif
Else if @SubjectName = 'Mathematics' then
If ks2ma ='' then
display 'No KS2'
else Ks2ma
endif
Else if @SubjectName <> 'English' and @SubjectName <> 'Mathematics' then
If ks2av ='' then
display 'No KS2'
else Ks2av
endif
到目前为止,这是我的代码,当@SubjectName = 'English' 时有效:
DECLARE
@DataCollection varchar(50) = '2013/14 - Autumn 1 - Targets',
@StuYear VARCHAR(2) = '11',
@SubjectName varchar(100) ='English',
@TeachingGroup varchar(25) = 'Select All',
@SubGroup varchar(10) = 'Select All'
SELECT CASE WHEN Ks2en = '' and @SubjectName = 'English' THEN 'No KS2' ELSE ks2en END AS 'KS2',
nullif(count(CASE WHEN result = '' THEN 1 END),0) AS 'No Level/Grade',
nullif(count(CASE WHEN result IN ('U', '1a', '1b', '1c') THEN 1 END),0) AS '1/U',
nullif(count(CASE WHEN result IN ('U', '2a', '2b', '2c') THEN 1 END),0) AS '2/U',
nullif(count(CASE WHEN result IN ('G-','3c') THEN 1 END),0) AS '3c/G-',
nullif(count(CASE WHEN result IN ('G', '3b') THEN 1 END),0) AS '3b/G',
nullif(count(CASE WHEN result IN ('G+','3a') THEN 1 END),0) AS '3a/G+',
nullif(count(CASE WHEN result IN( 'F-','4c') THEN 1 END),0) AS '4c/F-',
nullif(count(CASE WHEN result IN( 'F', '4b') THEN 1 END),0) AS '4b/F',
nullif(count(CASE WHEN result IN( 'F+', '4a') THEN 1 END),0) AS '4a/F+',
nullif(count(CASE WHEN result IN( 'E-', '5c') THEN 1 END),0) AS '5c/E-',
nullif(count(CASE WHEN result IN( 'E', '5b') THEN 1 END),0) AS '5b/E',
nullif(count(CASE WHEN result IN( 'E+', '5a') THEN 1 END),0) AS '5a/E+',
nullif(count(CASE WHEN result IN( 'D-', '6c') THEN 1 END),0) AS '6c/D-',
nullif(count(CASE WHEN result IN( 'D', '6b') THEN 1 END),0) AS '6b/D',
nullif(count(CASE WHEN result IN( 'D+', '6a') THEN 1 END),0) AS '6a/D+',
nullif(count(CASE WHEN result IN( 'C-', '7c') THEN 1 END),0) AS '7c/C-',
nullif(count(CASE WHEN result IN( 'C', '7b') THEN 1 END),0) AS '7b/C',
nullif(count(CASE WHEN result IN( 'C+', '7a') THEN 1 END),0) AS '7a/C+',
nullif(count(CASE WHEN result IN( 'B-', '8c') THEN 1 END),0) AS '8c/B-',
nullif(count(CASE WHEN result IN( 'B', '8b') THEN 1 END),0) AS '8b/B',
nullif(count(CASE WHEN result IN( 'B+', '8a') THEN 1 END),0) AS '8a/B+',
nullif(count(CASE result WHEN 'A-' THEN 1 END),0) AS 'A-',
nullif(count(CASE result WHEN 'A' THEN 1 END),0) AS 'A',
nullif(count(CASE result WHEN 'A+' THEN 1 END),0) AS 'A+',
nullif(count(CASE result WHEN 'A*-' THEN 1 END),0) AS 'A*-',
nullif(count(CASE result WHEN 'A*' THEN 1 END),0) AS 'A*'
FROM student JOIN subject
ON subject.upn=student.upn
WHERE
[StuYear] = @StuYear AND
[DataCollection] = @DataCollection AND
[Name] = @SubjectName AND (
@TeachingGroup = 'Select All' OR
[TeachingGroup] = @TeachingGroup
) AND (
@SubGroup = 'Select All' OR
Gender = CASE
WHEN @SubGroup = 'GenF' THEN 'F'
WHEN @SubGroup = 'GenM' THEN 'M'
END
)
GROUP BY ks2en
ORDER BY
CASE WHEN ks2en = 'W' THEN 0 ELSE 1 END,
LEFT(ks2en, 1),
RIGHT(ks2en, 1) DESC
如果 @SubjectName = 'Mathematics' 那么该语句将有效地执行与以下相同的操作:
DECLARE
@DataCollection varchar(50) = '2013/14 - Autumn 1 - Targets',
@StuYear VARCHAR(2) = '11',
@SubjectName varchar(100) ='Mathematics',
@TeachingGroup varchar(25) = 'Select All',
@SubGroup varchar(10) = 'Select All'
SELECT CASE WHEN Ks2ma = '' and @SubjectName = 'Mathematics' THEN 'No KS2' ELSE ks2ma END AS 'KS2',
nullif(count(CASE WHEN result = '' THEN 1 END),0) AS 'No Level/Grade',
**SNIP**
nullif(count(CASE result WHEN 'A*' THEN 1 END),0) AS 'A*'
FROM student JOIN subject
ON subject.upn=student.upn
WHERE
[StuYear] = @StuYear AND
[DataCollection] = @DataCollection AND
[Name] = @SubjectName AND (
@TeachingGroup = 'Select All' OR
[TeachingGroup] = @TeachingGroup
) AND (
@SubGroup = 'Select All' OR
Gender = CASE
WHEN @SubGroup = 'GenF' THEN 'F'
WHEN @SubGroup = 'GenM' THEN 'M'
END
)
GROUP BY ks2ma
ORDER BY
CASE WHEN ks2ma = 'W' THEN 0 ELSE 1 END,
LEFT(ks2ma, 1),
RIGHT(ks2ma, 1) DESC
如果@SubjectName 等于其他任何内容,例如科学、艺术或技术,那么 SQL 将如下所示:
DECLARE
@DataCollection varchar(50) = '2013/14 - Autumn 1 - Targets',
@StuYear VARCHAR(2) = '11',
@SubjectName varchar(100) ='Science',
@TeachingGroup varchar(25) = 'Select All',
@SubGroup varchar(10) = 'Select All'
SELECT CASE WHEN Ks2av = '' and @SubjectName <> 'Mathematics' and @SubjectName <> 'English' THEN 'No KS2' ELSE ks2av END AS 'KS2',
nullif(count(CASE WHEN result = '' THEN 1 END),0) AS 'No Level/Grade',
**SNIP**
nullif(count(CASE result WHEN 'A*' THEN 1 END),0) AS 'A*'
FROM student JOIN subject
ON subject.upn=student.upn
WHERE
[StuYear] = @StuYear AND
[DataCollection] = @DataCollection AND
[Name] = @SubjectName AND (
@TeachingGroup = 'Select All' OR
[TeachingGroup] = @TeachingGroup
) AND (
@SubGroup = 'Select All' OR
Gender = CASE
WHEN @SubGroup = 'GenF' THEN 'F'
WHEN @SubGroup = 'GenM' THEN 'M'
END
)
GROUP BY ks2av
ORDER BY
CASE WHEN ks2av = 'W' THEN 0 ELSE 1 END,
LEFT(ks2av, 1),
RIGHT(ks2av, 1) DESC
我的 SQL 生成的网格类似于下图。结果集看起来像 smae,但是背景数据将基于上面讨论的不同标准,并且会在每个单元格中产生不同的总数:
KS2 No Result 1/U 2/U 3c/G- 3b/G 3a/G+ 4c/F- 4b/F **snip**
No KS2 1 NULL NULL NULL NULL NULL NULL **snip**
2a NULL NULL NULL NULL NULL NULL 2 1 **snip**
3c 1 NULL NULL NULL NULL NULL NULL NULL **snip**
3b NULL NULL NULL NULL NULL NULL 1 NULL **snip**
3a 1 NULL NULL NULL NULL NULL NULL NULL **snip**
4c NULL 1 1 NULL NULL NULL NULL NULL **snip**
4b NULL NULL NULL NULL NULL NULL NULL NULL **snip**
4a NULL 1 1 NULL NULL NULL NULL NULL **snip**
5c NULL NULL NULL NULL NULL NULL NULL NULL **snip**
5b NULL NULL NULL NULL NULL NULL NULL NULL **snip**