我有这些table：

CREATE TABLE students(
  id int NOT NULL PRIMARY KEY,
  name VARCHAR(30) NOT NULL
 );

CREATE TABLE studentsActivities(
  studentId int NOT NULL,
  activity VARCHAR(30) NOT NULL,
  PRIMARY KEY (studentId, activity),
  foreign KEY (studentId) REFERENCES students(id) 
);

我还得把所有网球或足球的学生的名字都还给我。然而，有一个测试用例我不能通过，它是这样说的：
同名的学生。
我不知道测试用例的具体实现，但我怀疑是这样一种情况：一个叫卡尔的学生打网球，另一个叫卡尔的学生踢足球，卡尔被展示了两次。我怎样才能查询那个数据库得到这样的结果呢？我创建了演示库来尝试：

CREATE TABLE students(
  id int NOT NULL PRIMARY KEY,
  name VARCHAR(30) NOT NULL
 );

CREATE TABLE studentsActivities(
  studentId int NOT NULL,
  activity VARCHAR(30) NOT NULL,
  PRIMARY KEY (studentId, activity),
  foreign KEY (studentId) REFERENCES students(id) 
);

INSERT INTO students 
VALUES
(1, "Jeremy"),
(2, "Hannah"),
(3, "Luke"),
(4, "Frank"),
(5, "Sue"),
(6, "Sue"),
(7, "Peter");

INSERT INTO studentsActivities
VALUES
(1, "Tennis"),
(1, "Football"),
(2, "Running"),
(3, "Tennis"),
(4, "Football"),
(5, "Football"),
(6, "Tennis");

sql fiddle，假设传递集是：

Jeremy 
Luke 
Frank 
Sue 
Sue

我尝试过这两个问题，但都没有给出正确答案。

--- 1
SELECT s.name
FROM students s
JOIN studentsActivities sa
ON sa.studentId = s.id
WHERE activity = "Tennis"
UNION
SELECT s.name
FROM students s
JOIN studentsActivities sa
ON sa.studentId = s.id
WHERE activity = "Football"
--- Returns Frank Jeremy Luke Sue (missing one Sue)

--- 2
SELECT s.name
FROM students s
JOIN studentsActivities sa
ON sa.studentId = s.id
WHERE activity = "Tennis"
OR activity = "Football"
ORDER BY s.name;
--- Returns Frank Jeremy Jeremy Luke Sue Sue (too much Jeremies)