錯誤清單：
1、Invalid block tag on line 13: 'article.title', expected 'empty' or 'endfor'. Did you forget to register or load this tag?
2、{% include "article.html" %}引入頁面 為什麼内容為空，單獨建立一個url 打開就沒問題
3、django 多個條件查詢 TypeError: Object of type 'QuerySet' is not JSON serializable
4、django 多個條件查詢 django.core.exceptions.FieldError: Cannot resolve keyword 'depart' into field. Choices are: author, id, name
5、django 多個條件查詢 django.core.exceptions.FieldError: Related Field got invalid lookup: contains
6、module.py 反向關聯報錯
7、多對多關聯 ERRORS:<class 'proApp.admin.AuthorAdmin'>: (admin.E109) The value of 'list_display[8]' must not be a ManyToManyField.
8、通過接口擷取資料庫資料，某字段是多對多關系，報錯TypeError: Object of type 'ManyRelatedManager' is not JSON serializable
9、通過接口擷取資料庫資料，某字段是一對多關系，報錯TypeError: Object of type 'Publisher' is not JSON serializable
10、多對多 修改資料：TypeError: Direct assignment to the forward side of a many-to-many set is prohibited. Use author.set() instead.
11 、主鍵由自增改為手動：django.db.utils.InternalError: (1833, "Cannot change column 'id': used in a foreign key constraint 'proApp_author_book_book_id_b4feaab6_fk_proApp_book_id' of table 'python_sql.proapp_author_book'")
1、Invalid block tag on line 13: 'article.title', expected 'empty' or 'endfor'. Did you forget to register or load this tag?
<ul>
{% for article in article_list %}
<li>
<h3>{{ article.title }}</h3>
<p>{{ article.content }}</p>
</li>
{% endfor %}
</ul>
注意：
for循環語句 ：{% %}
字段取值： {{ }}
效果圖如下所示：
2、{% include "article.html" %}
引入頁面 為什麼内容為空，單獨建立一個url 打開就沒問題
def showArticle(request):
from proApp import models
article_list = models.Article.objects.all()
return render(request,"article.html",{"article_list":article_list})
解決辦法：
不需要在 def 中return render(傳回的是代碼片段)。正确代碼如下：
def addArticle(request):
title = request.POST.get("title")
content = request.POST.get("content")
dic = {'title': title, 'content': content}
models.Article.objects.create(**dic)
return HttpResponse("文章添加成功！") // 傳回的即是ajax 獲得data
3、django 多個條件查詢
問題1：TypeError: Object of type 'QuerySet' is not JSON serializable
解決辦法： https://blog.csdn.net/teavamc/article/details/77777301
問題2：中文獲得的是unicode
解決辦法：序列化時添加第三個參數 ensure_ascii
articleList = serializers.serialize("json",models.Article.objects.filter(title__contains=title).filter(content__contains=content),ensure_ascii=False)
問題3：ajax擷取的list資料 并不是對象形式 https://www.jb51.net/article/136971.htm
解決辦法：字元串 -> 字典形式
articleList = serializers.serialize("json",models.Article.objects.filter(title__contains=title).filter(content__contains=content),ensure_ascii=False)
articleList = json.loads(articleList)
data = {
'ret': {
'success': True,
'retCode': 200,
'retMsg': "文章查詢成功！"
},
'list': articleList
}
return HttpResponse(json.dumps(data), content_type='application/json; charset=utf-8')
4、django 多個條件查詢
問題：django.core.exceptions.FieldError: Cannot resolve keyword 'depart' into field. Choices are: author, id, name
解決辦法：
表連錯了
5、django 多個條件查詢
問題：django.core.exceptions.FieldError: Related Field got invalid lookup: contains
解決辦法：contains 是模糊搜尋，這裡部門值是絕對搜尋
depart = request.POST.get("depart")
search_sql = search_sql.filter(name__contains=name).filter(depart=depart)
6、module.py 反向關聯報錯：
解決辦法： 添加 related_name
class Book(models.Model):
author = models.ManyToManyField(Author,null=True,related_name='book_author')
class Author(models.Model):
book = models.ManyToManyField('Book',null=True,related_name='author_book')
7、ERRORS:<class 'proApp.admin.AuthorAdmin'>: (admin.E109) The value of 'list_display[8]' must not be a ManyToManyField.
admin.py： list_display 不可以輸出多對多關系表的字段
解決辦法：list_display 字段展示上不要加入 多對多關系的字段
8、通過接口擷取資料庫資料，某字段是多對多關系，報錯TypeError: Object of type 'ManyRelatedManager' is not JSON serializable
解決辦法：json.loads(serializers.serialize()) 轉一下資料類型即可
def getBook(request):
if request.method == "GET":
page = int(request.GET.get('page',''))-1
rows = int(request.GET.get('rows',''))
list = models.Book.objects.all().order_by("-id")
allList = []
for li in list:
author_list = json.loads(serializers.serialize("json", li.author.all(), ensure_ascii=False))
author_name = ''
author_id = []
for a in author_list:
author_id.append(a['pk'])
author_name += a['fields']['name'] + '、'
allList.append({
"id": li.id,
"name": li.name,
"price": li.price,
"saleNum": li.saleNum,
"publisher": li.publisher,
"author_id": author_id,
"author": author_name,
"publish_date": json.loads(json.dumps(li.publish_date, cls=DateEncoder)),
})
total = len(allList)
p = Datagrid()
json_data_list = p.page(page, rows, total, allList)
print (json_data_list)
return HttpResponse(json.dumps(json_data_list), content_type='application/json; charset=utf-8')
9、通過接口擷取資料庫資料，某字段是一對多關系，報錯TypeError: Object of type 'Publisher' is not JSON serializable
解決辦法：
資料原始字段：li.publisher， 但是因為是ForeignKey關聯其他表所得資料，并且預設外鍵為id
allList.append({
"id": li.id,
"name": li.name,
"price": li.price,
"saleNum": li.saleNum,
"publisher": li.publisher_id,
"publish_date": json.loads(json.dumps(li.publish_date, cls=DateEncoder)),
})
10、多對多：TypeError: Direct assignment to the forward side of a many-to-many set is prohibited. Use author.set() instead.
解決辦法：
1.getlist()
2.author[]
authors_list = request.POST.getlist("author[]")
11 、主鍵由自增改為手動：django.db.utils.InternalError: (1833, "Cannot change column 'id': used in a foreign key constraint 'proApp_author_book_book_id_b4feaab6_fk_proApp_book_id' of table 'python_sql.proapp_author_book'")
class Book(models.Model):
id = models.FloatField(primary_key=True)
book = models.Book.objects.all()
if len(book) > 0:
maxId = models.Book.objects.latest('id').id
else:
maxId = 0
maxId += 1
dic = {
'id': maxId,
}
b1 = models.Book(**dic)