Php 按聚合函数排序Laravel雄辩

您好，我想知道是否有可能使用Laravel的雄辩功能按聚合函数（MAX、MIN、COUNT）对查询结果进行分组/排序。这些模型是：

class School extends Model{
   function students(){
       return $this -> hasMany(Student::class);
   }
}
class Student extends Model{
   function school(){
       return $this -> belongsTo(School::class);
   }
}

经典的一对多关系，我想执行下一个查询：

School::select('school.*', 'MAX(student.score) as best_score') -> join('student', 'student.school_id', '=', 'school.id') -> orderByDesc('best_score') -> toSql()

select `school`.*, `MAX(student`.`score)` as `best_score` from `serije` inner join `student` on `student`.`school_id` = `school`.`id` order by `best_score` desc

所以我想列出所有拥有最好成绩学生的学校。Laravel雄辩地呈现下一个查询：

School::select('school.*', 'MAX(student.score) as best_score') -> join('student', 'student.school_id', '=', 'school.id') -> orderByDesc('best_score') -> toSql()

select `school`.*, `MAX(student`.`score)` as `best_score` from `serije` inner join `student` on `student`.`school_id` = `school`.`id` order by `best_score` desc

---

因此，他将

MAX（student

呈现为一列，这会引发sql错误，是否有任何方法可以绕过此而不使用集合，其想法是充分利用数据库。

您可以添加一个自定义属性，并对该自定义属性执行orderBy操作：

class School extends Model
{
    public function students()
    {
       return $this->hasMany(Student::class);
    }

    public function getHighestScoreAttribute()
    {
        $student = $this->students()->orderBy('score')->first();

        return $student ? $student->score : 0; 
    }
}
class Student extends Model{
    public function school()
    {
       return $this->belongsTo(School::class);
    }
}

// Query
$schools = School::orderBy('highestScore')->all();

---

您可以添加自定义属性，并在此自定义属性上执行orderBy操作：

class School extends Model
{
    public function students()
    {
       return $this->hasMany(Student::class);
    }

    public function getHighestScoreAttribute()
    {
        $student = $this->students()->orderBy('score')->first();

        return $student ? $student->score : 0; 
    }
}
class Student extends Model{
    public function school()
    {
       return $this->belongsTo(School::class);
    }
}

// Query
$schools = School::orderBy('highestScore')->all();

---

你可以很容易地在学校模型上检查这一点

public function students(){
   return $this->hasMany('App\Student','school_id','id')->orderByDesc('score');
}

---

使用（'students'）在控制器上调用此功能。

您可以在学校模型上轻松检查此功能

public function students(){
   return $this->hasMany('App\Student','school_id','id')->orderByDesc('score');
}

---

使用（'students'）在控制器上调用此函数。

好主意，但它会为每个学校实例调用查询吗？是的，它会，您可以使用即时加载。好主意，但它会为每个学校实例调用查询吗？是的，它会，您可以使用即时加载。