Relationships in Yii

BELONGS_TO: e.g. Student belongs to School

HAS_MANY: e.g. School has many Student

HAS_ONE: e.g. Teacher has at most one School

MANY_MANY: e.g. Student belongs to many Teacher and Teacher has many Student.

​​class Student extends CActiveRecord

{

  public function relations()

     {

  return array(

              'school'=>array(self::BELONGS_TO, 'School', 'school_id'),

              'teachers'=>array(self::MANY_MANY, 'Teacher','tbl_student_teacher(student_id, teacher_id)'),

         );

 }

}

class School extends CActiveRecord

{

    ......

    public function relations()

    {

        return array(

            'students'=>array(self::HAS_MANY, 'Student', 'school_id'),

            'teacher'=>array(self::HAS_ONE, 'Teacher', 'school_id'),

        );

    }

}