如何合並hasMany關系並在Laravel中返回關系？

Question

我正在嘗試合並2個集合，因為我需要搜索多列記錄，即team_one_id和team_two_id具體取決於它是客場還是主場比賽。

嘗試合並它們時，會在函數matches發生。 當我在第一個關系上調用merge時，函數matches不會返回實際關系，而是返回一個集合。

例外：

SQLSTATE[21000]: Cardinality violation: 1222 The used SELECT statements have a different number of columns (SQL: (select count(*) as aggregate from `matches` where `matches`.`team_one_id` = 1 and `matches`.`team_one_id` is not null and `winning_team_id` = 1) union (select * from `matches` where `matches`.`team_two_id` = 1 and `matches`.`team_two_id` is not null))

碼：

<?php

namespace App\Database;

use Illuminate\Database\Eloquent\Model;

class Team extends Model
{
    protected $primaryKey = 'id';

    protected $table = 'teams';
    public $timestamps = false;
    protected $guarded = ['id'];

    public function homeMatches() {
        return $this->hasMany('App\Database\Match', 'team_one_id');
     }

     public function awayMatches() {
        return $this->hasMany('App\Database\Match', 'team_two_id');
     }

     public function matches() {
        return $this->homeMatches()->union($this->awayMatches()->toBase());
     }
}

Answer 1

您可以嘗試以下方法：

 public function matches() {
    return $this->getRelationValue('homeMatches')->union($this->getRelationValue('awayMatches')->toBase());
 }

由於homeMatches（）函數返回一個Relation實例，但是dynamic屬性返回一個Collection。

Answer 2

雄辯的關系並非旨在匹配一個或另一個字段，而是被設計為具有一個外鍵。 您可以在方法內運行查詢以獲取所需的結果，而無需依賴關系。

如注釋中所述，如果您想重新使用該查詢，請將該邏輯包含在受保護的函數中。

 protected function allMatchesQuery()
 {
     // This needs to be wrapped in a nested query or else your orWhere will not be contained in parentheses.
     return Match::where(function($q) { 
          $q->where('team_one_id', $this->id)->orWhere('team_two_id', $this->id);
     });
 }

 public function getMatches() {
    return $this->allMatchesQuery()->get();
 }


 public function getRecentMatches() {
    return $this->allMatchesQuery()->orderBy('date', 'DESC')->limit(10)->get();
 }