django orm 操作表

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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‘)

# 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‘

# 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,

    # 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)

    # 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 )

# 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

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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