一、原生sql
# 原生sql（有些sql用orm写不出来） # 两种方案 # 第一种：用的比较少 # from django.db import connection # # cursor = connection.cursor(cursor=pymysql.cursors.DictCursor) # # cursor.execute("""SELECT * from app01_book where id = %s""", [1]) # # # row = cursor.fetchone() # row = cursor.fetchall() # print(row) # 第二种，用的多 # books=models.Book.objects.raw('select * from app01_book where id >3') # print(books)#RawQuerySet对象 # for book in books: # print(book.name) # books=models.Book.objects.raw('select * from app01_publish') # for book in books: # print(book.__dict__) # print(book.name) # print(book.addr) # print(book.email) # print(book.price) # authors = models.Author.objects.raw('SELECT app01_author.id,app01_author. NAME,app01_authordetail.sex FROM app01_author JOIN app01_authordetail ON app01_author.author_detail_id = app01_authordetail.id WHERE app01_authordetail.sex = 1') # # for author in authors: # print(author.name) # print(author.__dict__)
二、事务（请求，装饰器，局部）
# 事物：ACID，事物的隔离级别（搜），锁， 行级锁，表级锁 # djanog orm中使用事物：原子性操作，要么都成功，要么都失败 # 新增一个作者详情，新增一个作者 # 事物的三个粒度 # 1 局部使用 from django.db import transaction with transaction.atomic(): # 都在事物中，要么都成功，要么都失败 author_detail=models.AuthorDetail.objects.create(addr='xxx',phone='123',sex=1) # raise Exception('抛了异常') author=models.Author.objects.create(name='llqz',age=19,author_detail=author_detail) # 2 视图函数装饰器,这一个视图函数都在一个事物中 # @transaction.atomic # def index(request): # return HttpResponse('ok') # 3 整个http请求，在事物中，在setting.py中配置 ''' DATABASES = { 'default': { ... 'PORT': 3306, 'ATOMIC_REQUEST': True, } } 'ATOMIC_REQUEST': True, 设置为True统一个http请求对应的所有sql都放在一个事务中执行（要么所有都成功，要么所有都失败）。 '''