Fix ambiguities in teacher sql

orm/teacher.go

@@ -23,17 +23,17 @@ var (
 	selectUniqueTeacherClasses = `
 SELECT DISTINCT classes.* FROM activities 
 INNER JOIN classes on classes.id=activities.class_id 
-WHERE (teacher_id=? OR supply_teacher_id=?)`
+WHERE (activities.teacher_id=? OR activities.supply_teacher_id=?)`
 
 	selectUniqueTeacherSubjects = `
 SELECT DISTINCT subjects.* FROM activities 
 INNER JOIN subjects on subjects.id=activities.subject_id 
-WHERE (teacher_id=? OR supply_teacher_id=?)`
+WHERE (activities.teacher_id=? OR activities.supply_teacher_id=?)`
 
 	selectUniqueTeacherStudents = `
 SELECT DISTINCT students.* FROM activities 
 INNER JOIN students on students.id=activities.student_id 
-WHERE (teacher_id=? OR supply_teacher_id=?)`
+WHERE (activities.teacher_id=? OR activities.supply_teacher_id=?)`
 )
 
 func (t *Teacher) GetID() uint { return t.ID }