第二次修改models.py以后再次

python manage.py makemigrations

提示如下

You are trying to add a non-nullable field ’address’ to xc_users without a default; we can’t do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows) 2) Qu

于是刪除數據庫表，繼續報相同的錯誤

makemigration需要指定名稱，然后migrate才能識別兩次<span style='font-family: Arial, Helvetica, sans-serif;'>makemigrations的不同</span>

python manage.py makemigrations --name sqlname

然后再執行：

python manage.py migrate

成功解決問題！

補充知識：django rest framework如何一次性序列化同一個數據庫下多個model表數據在一個json頁面下

在django項目中，首先我們要安裝django-rest-mutiple-models

pip install django-rest-multiple-models

然后在setting配置中配置一下APP

INSTALLED_APPS = ( .... ’drf_multiple_model’,)

在我們的views視圖函數下引入

from drf_multiple_model.views import ObjectMultipleModelAPIView

如下兩個模型

class Play(models.Model): genre = models.CharField(max_length=100) title = models.CharField(max_length=200) pages = models.IntegerField() class Poem(models.Model): title = models.CharField(max_length=200) style = models.CharField(max_length=100) lines = models.IntegerField() stanzas = models.IntegerField()

序列化如下

class PlaySerializer(serializers.ModelSerializer): class Meta: model = Play fields = (’genre’,’title’,’pages’) class PoemSerializer(serializers.ModelSerializer): class Meta: model = Poem fields = (’title’,’stanzas’)

views中我們可以這么寫，繼承一個ObjectMutipleModelAPIView

from drf_multiple_model.views import ObjectMultipleModelAPIView class TextAPIView(ObjectMultipleModelAPIView): querylist = [ {’queryset’: Play.objects.all(), ’serializer_class’: PlaySerializer}, {’queryset’: Poem.objects.filter(style=’Sonnet’), ’serializer_class’: PoemSerializer}, .... ]

如果我們使用的url是router，那這里我們就應該繼承ObjectMutipleModelAPIViewset

具體的引入

from drf_multiple_model.viewsets import ObjectMultipleModelAPIViewSet

DRF頁面的顯示效果如下

{ 'Play' : [ {'genre': 'Comedy', 'title': 'A Midsummer Night's Dream', 'pages': 350}, {'genre': 'Tragedy', 'title': 'Romeo and Juliet', 'pages': 300}, .... ], 'Poem' : [ {'title': 'Shall I compare thee to a summer's day', 'stanzas': 1}, {'title': 'As a decrepit father takes delight', 'stanzas': 1}, .... ],}

效果就是能在一個json頁面下序列化出多個不同的model數據

我們還可以對每個表的數據進行分頁

from drf_multiple_model.pagination import MultipleModelLimitOffsetPagination

views下可以這么寫

class LimitPagination(MultipleModelLimitOffsetPagination):default_limit = 10

意思是每個model默認顯示前十條數據

如果前端需要，url上可以加上limit=5，自定義默認顯示前五條數據

更多詳細內容，github搜索DjangoRestMultipleModels

以上這篇django修改models重建數據庫的操作就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持好吧啦網。