Django的ORM select_related呈現模板

Question

我在Django 1.10版本

class Game(models.Model): 
    game_code = models.CharField(max_length=10) 
    home_team = models.ForeignKey(Team, related_name="home_set", default=2, blank=True, null=True) 
    away_team = models.ForeignKey(Team, related_name="away_set", default=2, blank=True, null=True) 


class GameCoefficient(models.Model): 
    game = models.ForeignKey(Game, default=3) 
    win_type = models.CharField(choices=win_type, max_length=250, blank=True, null=True, default="") 
    value = models.FloatField(max_length=250, blank=True, null=True, default="") 

這款車型這個ORM查詢

class BaseView(View): 
    data = dict() 
    template = "index.html" 
    def get(self, request): 
     self.data['coefficents_and_game'] = GameCoefficient.objects.all().select_related('game') 
     return render_to_response(self.template, self.data) 

我能得到的係數，並顯示他們的比賽之後。現在在模板顯示中重複「game_code」。我發現很難顯示遊戲及其係數。

Answer 1

可能更容易爲你的遊戲查詢集發送到模版。

class BaseView(View): 
    data = dict() 
    template = "index.html" 
    def get(self, request): 
     self.data['games'] = Game.objects.prefetch_related('gamecoefficient_set').all() 
     return render_to_response(self.template, self.data) 

使用模板，如：

{% for game in games %} 
    {{ game.game_code }} 
    {% for coeff in game.gamecoefficient_set.all %} 
    {{ coeff.value }} 
    {% endfor %} 
{% endfor %} 

更新：新增prefetch_related爲DB-查詢優化