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Laravel5 关联查询 —— 多级一对多的实现

Laravel

例如一个学校，学校有许多年级，年级有许多班级，班级里有许多老师，那么这种多级的多对一该怎么实现呢？
1.先设置他们的Model
学校的： School.PHP

[php]view plain copy print ?

  3. namespace App;
  5. use Illuminate\Database\Eloquent\Model;
  7. class schoolClass extends Model
  8. {
  9. protected $table = 'schools';
  11. public function hasManyGrades(
  12. {
  13. return $this->hasMany('App\Grade', 'school_id', 'id');
  14. }
  15. }


年级的：Grade.php

[php]view plain copy print ?
  3. namespace App;
  5. use Illuminate\Database\Eloquent\Model;
  7. class Grade extends Model
  8. {
  9. protected $table = 'grades';
  11. public function hasManyClasses()
  12. {
  13. return $this->hasMany('App\schoolClass', 'grade_id', 'id');
  14. }
  15. }



班级的：schoolSchool.php

[php]view plain copy print ?
  3. namespace App;
  5. use Illuminate\Database\Eloquent\Model;
  7. class schoolClass extends Model
  8. {
  9. protected $table = 'jjxiao_classes';
  11. public function hasManyTeachers()
  12. {
  13. return $this->hasMany('App\Teacher', 'class_id', 'id');
  14. }
  15. }



老师的：Teacher.php

[php]view plain copy print ?
  3. namespace App;
  5. use Illuminate\Database\Eloquent\Model;
  7. class Teacher extends Model
  8. {
  9. protected $table = 'jjxiao_teacher_staffs';
  11. }



2.控制器里面查出 【Laravel5 关联查询 —— 多级一对多的实现】
[php]view plain copy print ?
  1. public function index(){
  2. $id=1;
  3. $school=School::find($id);
  4. $grades=$school->hasManyGrades()->get(); //找到所有的年级
  6. foreach($grades as $g){
  7. $classes[]=$g->hasManyClasses()->get(); //每个年级找到所对应的班级
  8. }
  10. foreach ($classes as $cl) {
  11. foreach($cl as $c){
  12. $teachers[]=$c->hasManyTeachers()->get(); //每个班级找到老师
  13. }
  14. }
  16. foreach ($teachers as $te) {//给数组脱维
  17. foreach($te as $t){
  18. $teacher[]=$t;
  19. }
  20. }
  21. return view('home.myschool_teacher.index')
  22. ->withGrade($grades)
  23. ->withTeacher($teacher);
  24. }

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