Sql server 使用MSSQL统计ID的唯一出现次数

我试图统计每年教师的独特事件。我相信结果不是独一无二的

我的问题

SELECT DISTINCT count (tblTeachers.TeacherID) AS uniqueTeacherCount, tblSchoolYears.SchoolYear

FROM tblTeachers INNER JOIN tblTeacher_Building 
.
.

GROUP BY tblSchoolYears.SchoolYear
ORDER BY tblSchoolYears.SchoolYear DESC;

结果（计算TeacherID的重复项）

我也试过了

SELECT COUNT(DISTINCT tblTeachers.TeacherID) AS uniqueTeacherCount, tblSchoolYears.SchoolYear

FROM tblTeachers INNER JOIN tblTeacher_Building 
.
.

GROUP BY tblSchoolYears.SchoolYear
ORDER BY tblSchoolYears.SchoolYear DESC;

我错过了什么

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谢谢

很接近了。我想这就是你想要的：

Select Count(TeacherID) AS uniqueTeacherCount,SchoolYear
from
(
SELECT DISTINCT tblTeachers.TeacherID, tblSchoolYears.SchoolYear
FROM tblTeachers INNER JOIN tblTeacher_Building 
.
.
) hlp
GROUP BY SchoolYear
ORDER BY SchoolYear DESC;

SELECT COUNT(*)
FROM
(
SELECT DISTINCT count (tblTeachers.TeacherID) AS uniqueTeacherCount, tblSchoolYears.SchoolYear ...
)

---

你很接近。我想这就是你想要的：

SELECT COUNT(*)
FROM
(
SELECT DISTINCT count (tblTeachers.TeacherID) AS uniqueTeacherCount, tblSchoolYears.SchoolYear ...
)

---

这是

sql server

还是

ms access

？如果您想要访问查询，您不能

使用Count（DISTINCT…

这是

sql server

还是

ms access

？如果您想要访问查询，您不能

使用Count（DISTINCT…