Laravel group by，在不同表中有关系
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Laravel group by, with relationship in different tables
提问by Geoff
I am using laravel eloquent, trying to fetch information contained in different tables and compare them.
我正在使用 laravel eloquent，试图获取包含在不同表中的信息并进行比较。
My tables are
我的桌子是
tbl_checks
id,check_id, person_id //person_id is the foreign key
tbl_persons
id, category,
I would like to fetch all people in table tbl_checksand group the data by person category tbl_persons.category.
我想获取表中的所有人tbl_checks并按人员类别对数据进行分组tbl_persons.category。
In normal SQL statement it's like:
在普通的 SQL 语句中，它是这样的：
select from tbl_checks group by tbl_person.category where the tbl_persons.id is contained in tbl_checks.person_id
In my models I have:
在我的模型中，我有：
class PersonsModel extends Model {
//connect to the next database
protected $connection = 'inspection';
protected $table = 'tbl_trucks';
//relation with tbl_checks
public function checks(){
return $this->hasMany('App\TblChecks','person_id','id');
}
}
How can I use the ELoquent model, and not the Db facade? To make it abit clear. Am trying to find all persons who are in the table_checks and ignore persons id who are not in tbl_checks
如何使用 ELoquent 模型，而不是 Db 外观？说得清楚一点。我正在尝试查找 table_checks 中的所有人员并忽略不在 tbl_checks 中的人员 ID
回答by Jonas Staudenmeir
Assuming you have a personrelationship in your TblChecksmodel:
假设您person的TblChecks模型中有一个关系：
TblChecks::with('person')->get()->groupBy('person.category');
回答by Ben
If you are using Laravel >= 5.3, use Eloquent::has(Querying Relationship Existence):
如果您正在使用Laravel >= 5.3，请使用Eloquent::has（查询关系存在）：
$persons = PersonsModel::has('checks')->get();
For Laravel < 5.3, use Where Exists Clauses:
对于Laravel < 5.3，使用Where Exists 子句：
$persons = PersonsModel::whereExists(function ($q) {
$q->select(DB::raw(1))->from('tbl_checks')
->whereRaw('tbl_persons.id=tbl_checks. person_id');
})->get();
