Question

这是我的代码。它总共109行。

1

SELECT DISTINCT(SELECT top 1 lastname+', '+firstname FROM users WHERE privilege not in 
('Counselor','Guardian') AND userindex IN (SELECT userindex FROM studenttouser 
WHERE studentindex = students.studentindex)) AS teacher

这段代码给了我9行教师的名字。

2

SELECT COUNT(students.lastname) as total_student
from table
where (SELECT top 1 lastname+', '+firstname FROM users WHERE privilege not in 
('Counselor','Guardian') AND userindex IN (SELECT userindex FROM studenttouser 
WHERE studentindex = students.studentindex))='sam'

这段代码给了我

column1
  34

问题是如何结合在一起。 COUNT students.name-column1，DISTINCT teacher-column2

我只需要名单和总数。例如;

name     total_student
sam          24
John         35
Julie        34

等...... 我和计票学生一起遇到了麻烦。它本身就可以，但是当我使用DISTINCT和COUNT时它会给我一个错误。

我试过

SELECT COUNT(students.lastname) as Student_total, 
DISTINCT(SELECT top 1 lastname+', '+firstname FROM users 
WHERE privilege not in 
('Counselor','Guardian') AND userindex IN (SELECT userindex FROM studenttouser 
WHERE studentindex = students.studentindex)) AS teacher

不起作用。 HELP !!!

Answer 1

您需要使用Join和Group By。我不能确定除非知道你的表结构和数据库设计，因为这个表似乎有点复杂，因为它需要自联接。你可以尝试这些方面的东西。

SELECT Name, total_student

FROM
(
SELECT DISTINCT(SELECT top 1 lastname+', '+firstname as Name
FROM users WHERE privilege not in 
   ('Counselor','Guardian') AND userindex IN (SELECT userindex FROM studenttouser 
   WHERE studentindex = students.studentindex))
) teacher

INNER JOIN
(
SELECT COUNT(students.lastname) as total_student
from table 
) as Student 
ON (SELECT top 1 lastname+', '+firstname 
FROM users 
WHERE privilege not in ('Counselor','Guardian') AND userindex IN (SELECT userindex FROM studenttouser 
WHERE studentindex = students.studentindex)
   )=teacher.Name

GROUP BY teacher.Name

sql server 2008，COUNT和DISTINCT结合在一起

1 个答案: