django orm 操作表
django orm 操作表
1、基本操作
- 增
models.Tb1.objects.create(c1='xx', c2='oo') 增加一条数据，可以接受字典类型数据 **kwargs insert into Tb1 (c1,c2) values ('xx','00') obj = models.Tb1(c1='xx', c2='oo') obj.save() insert into Tb1 (c1,c2) values ('xx','00') # get_or_create() 如果纯在则获取，否者创建 obj, created = models.UserInfo.objects.get_or_create(name='summer1', defaults={'age':123,'pwd':'ab456'}) # 先根据条件去查，如果存在name='summer1'，则后面的default无效不执行。 print(obj,created) # created 为True或False # update_or_create() 如果存在，则更新，否则，创建 obj, created = models.UserInfo.objects.update_or_create(name='summer1', defaults={'age':123,'pwd':'ab456'}) print(obj,created)
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- 查
models.Tb1.objects.get(id=123) # 获取单条数据，不存在则报错（不建议） select * from Tb1 where id=123 limit 1 models.Tb1.objects.all() # 获取全部 select * from Tb1 models.Tb1.objects.filter(name='seven') # 获取指定条件的数据 select * from Tb1 where name='seven' # exists() # 检查查询结果是否存在，返回True或False result = models.UserInfo.objects.filter(id=1111).exists() print(result)
- 删
models.Tb1.objects.filter(name='seven').delete() # 删除指定条件的数据 delete from Tb1 where name='seven'
- 改
models.Tb1.objects.filter(name='seven').update(gender='0') # 将指定条件的数据更新，均支持 **kwargs update Tb1 set gender='0' where name='seven' obj = models.Tb1.objects.get(id=1) obj.c1 = '111' obj.save() # 修改单条数据 update Tb1 set c1 = '111' where id=1
2、进阶操作（了不起的双下划线）
利用双下划线将字段和对应的操作连接起来
-
获取个数
models.Tb1.objects.filter(name='seven').count() select count(*) from Tb1 where name='seven'
-
大于，小于
models.Tb1.objects.filter(id__gt=1) # 获取id大于1的值 select * from Tb1 where id>1 models.Tb1.objects.filter(id__gte=1) # 获取id大于等于1的值 select * from Tb1 where id>=1 models.Tb1.objects.filter(id__lt=10) # 获取id小于10的值 select * from Tb1 where id<10 models.Tb1.objects.filter(id__lte=10) # 获取id小于等于10的值 select * from Tb1 where id<=10 models.Tb1.objects.filter(id__lt=10, id__gt=1) # 获取id大于1 且 小于10的值 select * from Tb1 where id<10 and id>1
-
in
models.Tb1.objects.filter(id__in=[11, 22, 33]) # 获取id等于11、22、33的数据 select * from Tb1 where id in (11, 22, 33) models.Tb1.objects.exclude(id__in=[11, 22, 33]) # not in select * from Tb1 where id not in (11, 22, 33)
-
isnull
Entry.objects.filter(pub_date__isnull=True) select * from Tb1 where pub_date is null
-
contains
models.Tb1.objects.filter(name__contains="ven") select * from Tb1 where name like binary '%ven%' models.Tb1.objects.filter(name__icontains="ven") # icontains大小写不敏感 select * from Tb1 where name like '%ven%' models.Tb1.objects.exclude(name__icontains="ven") select * from Tb1 where name not like '%ven%'
-
range
models.Tb1.objects.filter(id__range=[1, 2]) # 范围bettwen and select * from Tb1 where id bettwen 1 and 2
-
其他类似
startswith，istartswith, endswith, iendswith, startswith select * from Tb1 where name like 'ven%' endswith select * from Tb1 where name like '%ven'
-
order by
models.Tb1.objects.filter(name='seven').order_by('id') # asc select * from Tb1 where name='seven' order by id asc models.Tb1.objects.filter(name='seven').order_by('-id') # desc select * from Tb1 where name='seven' order by id desc
-
group by
from django.db.models import Count, Min, Max, Sum models.Tb1.objects.filter(c1=1).values('id').annotate(c=Count('num')) SELECT "app01_tb1"."id", COUNT("app01_tb1"."num") AS "c" FROM "app01_tb1" WHERE "app01_tb1"."c1" = 1 GROUP BY "app01_tb1"."id"
-
limit 、offset
models.Tb1.objects.all()[10:20] select * from Tb1 limit 10,20
-
regex正则匹配，iregex 不区分大小写
Entry.objects.get(title__regex=r'^(An?|The) +') select * from Entry where title regexp binary "^(An?|The) +" Entry.objects.get(title__iregex=r'^(an?|the) +') select * from Entry where title regexp "^(An?|The) +"
-
date
Entry.objects.filter(pub_date__date=datetime.date(2005, 1, 1)) Entry.objects.filter(pub_date__date__gt=datetime.date(2005, 1, 1)) -
year
Entry.objects.filter(pub_date__year=2005) Entry.objects.filter(pub_date__year__gte=2005) -
month
Entry.objects.filter(pub_date__month=12) Entry.objects.filter(pub_date__month__gte=6) -
day
Entry.objects.filter(pub_date__day=3) Entry.objects.filter(pub_date__day__gte=3) -
week_day
Entry.objects.filter(pub_date__week_day=2) Entry.objects.filter(pub_date__week_day__gte=2) -
hour
Event.objects.filter(timestamp__hour=23) Event.objects.filter(time__hour=5) Event.objects.filter(timestamp__hour__gte=12)
-
minute
Event.objects.filter(timestamp__minute=29) Event.objects.filter(time__minute=46) Event.objects.filter(timestamp__minute__gte=29)
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second
Event.objects.filter(timestamp__second=31) Event.objects.filter(time__second=2) Event.objects.filter(timestamp__second__gte=31)
3、其他操作
-
extra
extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None) Entry.objects.extra(select={'new_id': "select col from sometable where othercol > %s"}, select_params=(1,)) Entry.objects.extra(where=['headline=%s'], params=['Lennon']) Entry.objects.extra(where=["foo='a' OR bar = 'a'", "baz = 'a'"]) Entry.objects.extra(select={'new_id': "select id from tb where id > %s"}, select_params=(1,), order_by=['-nid'])
-
F
from django.db.models import F models.Tb1.objects.update(num=F('num')+1) update Tb1 set num=num+1
-
Q
from django.db.models import Q 方式一： Q(nid__gt=10) Q(nid=8) | Q(nid__gt=10) select * from table where nid=8 or nid>10 Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption='root') select * from Tb1 where (nid=8 or nid>10) and caption='root' 方式二： con = Q() q1 = Q() q1.connector = 'OR' q1.children.append(('id', 1)) q1.children.append(('id', 10)) q1.children.append(('id', 9)) q2 = Q() q2.connector = 'OR' q2.children.append(('c1', 1)) q2.children.append(('c1', 10)) q2.children.append(('c1', 9)) con.add(q1, 'AND') con.add(q2, 'AND') models.Tb1.objects.filter(con) select * from Tb1 where ( id=1 or id=10 or id=9 ) and ( c1=1 or c1=10 or c1=9 )
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执行原生SQL
from django.db import connection, connections cursor = connection.cursor() # cursor = connections['default'].cursor() cursor.execute("""SELECT * from auth_user where id = %s""", [1]) row = cursor.fetchone()
4、连表操作（了不起的双下划线）
利用双下划线和 _set 将表之间的操作连接起来
- 表结构实例
class UserProfile(models.Model): user_info = models.OneToOneField('UserInfo') username = models.CharField(max_length=64) password = models.CharField(max_length=64) def __str__(self): return self.username class UserInfo(models.Model): user_type_choice = ( (0, '普通用户'), (1, '高级用户'), ) user_type = models.IntegerField(choices=user_type_choice) name = models.CharField(max_length=32) email = models.CharField(max_length=32) address = models.CharField(max_length=128) def __str__(self): return self.name class UserGroup(models.Model): caption = models.CharField(max_length=64) user_info = models.ManyToManyField('UserInfo') def __str__(self): return self.caption class Host(models.Model): hostname = models.CharField(max_length=64) ip = models.GenericIPAddressField() user_group = models.ForeignKey('UserGroup') def __str__(self): return self.hostname
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一对一操作
user_info_obj = models.UserInfo.objects.filter(id=1).first() print (user_info_obj.user_type) select user_type drom UserInfo where id=1 limit 1 print (user_info_obj.get_user_type_display()) print (user_info_obj.userprofile.password) select userprofile.password from userprofile,UserInfo where UserInfo.id=1 and UserInfo.id=userprofile.user_info user_info_obj = models.UserInfo.objects.filter(id=1).values('email', 'userprofile__username').first() select email, userprofile.username from UserInfo,userprofile where UserInfo.id=1 and UserInfo.id=userprofile.user_info print (user_info_obj.keys()) print (user_info_obj.values())
-
一对多
类似一对一 1、搜索条件使用 __ 连接 2、获取值时使用 . 连接 -
多对多操作
user_info_obj = models.UserInfo.objects.get(name=u'武沛齐') user_info_objs = models.UserInfo.objects.all() group_obj = models.UserGroup.objects.get(caption='CEO') group_objs = models.UserGroup.objects.all() # 添加数据 group_obj.user_info.add(user_info_obj) group_obj.user_info.add(*user_info_objs) # 删除数据 group_obj.user_info.remove(user_info_obj) group_obj.user_info.remove(*user_info_objs) # 添加数据 user_info_obj.usergroup_set.add(group_obj) user_info_obj.usergroup_set.add(*group_objs) # 删除数据 user_info_obj.usergroup_set.remove(group_obj) user_info_obj.usergroup_set.remove(*group_objs) # 获取数据 print group_obj.user_info.all() print group_obj.user_info.all().filter(id=1) # 获取数据 print user_info_obj.usergroup_set.all() print user_info_obj.usergroup_set.all().filter(caption='CEO') print user_info_obj.usergroup_set.all().filter(caption='DBA')
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