我在网上搜索了我的问题，但我找不到答案。我找到了一个关于StackOverflow的教程，但对于我的例子来说，它不起作用。
当我运行以下代码时，它返回NULL:
$data['lessons']->student
我想要得到什么:
ID |日期|用户。firstname | Teacher.firstname
我代码:
我有3个表:
- 课程{id，日期，fk_students_id, fk_teachers_id}
- student {id, firstname}
- 老师{id, firstname}
模型em> Lesson.php :
public function student(){
return $this->belongsTo('App'Student');
}
public function teacher(){
return $this->belongsTo('App'Teacher');
}
模型em> Student.php :
public function lessons(){
return $this->hasMany('App'Lesson', 'fk_students_id');
}
模型em> Teacher.php :
public function lessons(){
return $this->hasMany('App'Lesson', 'fk_teachers_id');
}
在Controller:
$data['lessons'] = Lesson::with(['student', 'teacher'])->first();
return var_dump($data['lessons']->student);
dd($data);输出:
array:1 [
"lessons" => Lesson {#303
#connection: null
#table: null
#primaryKey: "id"
#perPage: 15
+incrementing: true
+timestamps: true
#attributes: array:10 [
"id" => 1
"date" => "2015-07-25"
"start" => "12:30:00"
"end" => "13:00:00"
"fk_students_id" => 1
"fk_teachers_id" => 1
"lesson_array" => "[{"id":"1", "result":"0"},{"id":"2", "result":"1"},{"id":"15", "result":"2"}]"
"slug" => "562153eae355e"
"created_at" => "0000-00-00 00:00:00"
"updated_at" => "0000-00-00 00:00:00"
]
#original: array:10 [
"id" => 1
"date" => "2015-07-25"
"start" => "12:30:00"
"end" => "13:00:00"
"fk_students_id" => 1
"fk_teachers_id" => 1
"lesson_array" => "[{"id":"1", "result":"0"},{"id":"2", "result":"1"},{"id":"15", "result":"2"}]"
"slug" => "562153eae355e"
"created_at" => "0000-00-00 00:00:00"
"updated_at" => "0000-00-00 00:00:00"
]
#relations: array:2 [
"student" => null
"teacher" => null
]
#hidden: []
#visible: []
#appends: []
#fillable: []
#guarded: array:1 [
0 => "*"
]
#dates: []
#casts: []
#touches: []
#observables: []
#with: []
#morphClass: null
+exists: true
}
]
谢谢你的帮助!
如你所见，
#relations: array:2 [
"student" => null
"teacher" => null
]
都是空的，这是因为外键的名字。
所以你应该在模型上设置它们:
public function student(){
return $this->belongsTo('App'Student', 'fk_teachers_id', 'id');
}
public function teacher(){
return $this->belongsTo('App'Teacher', 'fk_students_id','id');
}