laravel orm 关联条件查询代码

public function a(){  return $this->belongsTo('App/Models/a', 'aid');}$model = $this->whereHas('a', function ($query) use ($search) {  $query->where('username', 'like', '%' . $search['username'] . '%');})->with(['a:id,username'])->get();

select a.id,a.username,b.* from b left join a on a.id = b.aid where a.username like "%username%";