从表中选择一个字段具有相同值的行

您必须加入反对自己的学生的行列：

SELECt s1.initials, s1.lastNameFROM Student s1, Student s2WHERe s1.studentId <> s2.studentID AND s1.tutorId = s2.tutorid

如果要输出对：

SELECt s1.initials, s1.lastName, s2.initials, s2.lastNameFROM Student s1, Student s2WHERe s1.studentId <> s2.studentID AND s1.tutorId = s2.tutorid

要获取导师列表-学生，请执行以下操作：

SELECt tutorId, GROUP_CONCAt( initials, lastName SEPARATOR ', ') FROM `Student` GROUP BY tutorId