以上运算符都区分大小写，在这些运算符前加上i表示不区分大小写，

如iexact、icontains、istartswith、iendswith.

insert into tb_bookinfo()values()

新增--save

book = BooksInfo(

bookname = '红楼梦',

bookpubtime = date(1930,9,1),

bookauthor = '曹雪芹'

)

character = CharacterInfo(

charactername = '猪八戒',

charactergender = 1,

characterage = 55,

chac_description = '猪悟能',

cbook = book

)

新增--create

CharacterInfo.objects.create(

charactername = '女儿国国王',

charactergender = 1,

characterage = 20,

chac_description = '女儿美',

cbook = book

)

查询多条记录--返回的是列表

BooksInfo.objects.all()

CharacterInfo.objects.all()

查询记录条数

BooksInfo.objects.count()

CharacterInfo.objects.count()

查询单条记录

book = BooksInfo.objects.get(bookname = '西游记')

BooksInfo.objects.get(id=1)

BooksInfo.objects.filter(id__exact=1)

模糊查询

BooksInfo.objects.filter(bookname__contains='梦')

BooksInfo.objects.filter(bookname__endswith='义')

BooksInfo.objects.filter(bookname__startswith='西')

BooksInfo.objects.filter(bookname__istartswith='西')

空查询

BooksInfo.objects.filter(bookname__isnull = False)

范围查询

BooksInfo.objects.filter(id__in=[1,2,4])

属性与常量之间的比较查询：大于，大于等于，小于，小于等于,exclude

BooksInfo.objects.filter(id__gt=3)

BooksInfo.objects.filter(id__gte=2)

BooksInfo.objects.filter(id__lt=3)

BooksInfo.objects.filter(id__lte=3)

BooksInfo.objects.exclude(id=1)

日期查询

year、month、day、week_day、hour、minute、second：对日期时间类型的属性进行运算

BooksInfo.objects.filter(bookpubtime__year=1930)

BooksInfo.objects.filter(bookpubtime__gt=date(1930,9,1))

属性与属性的比较：F(属性名)

from django.db.models import F

BooksInfo.objects.filter(bookcommentcount__gte=F('bookreadcount'))

BooksInfo.objects.filter(bookcommentcount__gte=F('bookreadcount')*2)

and 查询

BooksInfo.objects.filter(bookauthor__contanins='罗',bookname__startswith='三')

or查询Q(属性名__运算符=值)使用&、|连接，&表示逻辑与，|表示逻辑或,~操作符表示非not

BooksInfo.objects.filter(Q(bookreadcount__gt=300)|Q(bookname__contains='吴'))

BooksInfo.objects.filter(~Q(pk=3))

BooksInfo.objects.filter(~Q(id=3))

聚合查询--返回的是字典

BooksInfo.objects.aggregate(Sum('bookreadcount'))

使用count时一般不使用aggregate()过滤器

BooksInfo.objects.count()

排序

BooksInfo.objects.all().order_by('bookreadcount')

BooksInfo.objects.all().order_by('-bookreadcount')

关联查询语法:一到多,多的模型类名小写

一对应的模型类对象.多对应的模型类名小写_set

b = BooksInfo.objects.get(id=1)

b.characterinfo_set.all()

多到一

c = CharacterInfo.objects.get(id=1)

c.cbook

访问一模型的id:多对应的模型类对象.关联类属性_id

c.cbook_id

关联过滤查询：多的模型类名小写

BooksInfo.objects.filter(characterinfo__charactername='贾宝玉')

BooksInfo.objects.filter(characterinfo__charactername__contains='玉')

BooksInfo.objects.filter(characterinfo__characterage__gt=30)

修改：单条修改

c = CharacterInfo.objects.get(charactername='猪八戒')

c.charactername='猪哥哥'

c.save()

批量修改

CharacterInfo.objects.filter(charactername='林黛玉').update(charactername='林妹妹')

删除：

模型类对象delete

c = CharacterInfo.objects.get(id=3)

c.delete()

模型类.objects.filter().delete()

CharacterInfo.objects.filter.(id=14).delete()

Django查询结果集

BooksInfo.objects.all()

BooksInfo.objects.filter(bookreadcount__gt=30).order_by('bookpubtime')

b = BooksInfo.objects.exclude(bookname__contains='三')

确定查询集中是否有数据

b.exists()