标签:http 连接 exception class 无符号 唯一索引 查找 cond unique
ORM基本增删改查操作:
# 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 obj = models.Tb1(c1=‘xx‘, c2=‘oo‘) obj.save() # 查 models.Tb1.objects.get(id=123) # 获取单条数据,不存在则报错(不建议) models.Tb1.objects.all() # 获取全部 models.Tb1.objects.filter(name=‘seven‘) # 获取指定条件的数据 models.Tb1.objects.exclude(name=‘seven‘) # 获取指定条件的数据 # 删 models.Tb1.objects.filter(name=‘seven‘).delete() # 删除指定条件的数据 # 改 models.Tb1.objects.filter(name=‘seven‘).update(gender=‘0‘) # 将指定条件的数据更新,均支持 **kwargs obj = models.Tb1.objects.get(id=1) obj.c1 = ‘111‘ obj.save()# 修改单条数据
ORM进阶操作:
# 获取个数 models.Tb1.objects.filter(name=‘seven‘).count() # 大于,小于 models.Tb1.objects.filter(id__gt=1) # 获取id大于1的值 models.Tb1.objects.filter(id__gte=1) # 获取id大于等于1的值 models.Tb1.objects.filter(id__lt=10) # 获取id小于10的值 models.Tb1.objects.filter(id__lte=10) # 获取id小于10的值 models.Tb1.objects.filter(id__lt=10, id__gt=1) # 获取id大于1 且 小于10的值 # in models.Tb1.objects.filter(id__in=[11, 22, 33]) # 获取id等于11、22、33的数据 models.Tb1.objects.exclude(id__in=[11, 22, 33]) # not in # isnull models.Entry.objects.filter(pub_date__isnull=True) # contains() models.Tb1.objects.filter(name__contains="ven") models.Tb1.objects.filter(name__icontains="ven") # icontains大小写不敏感 models.Tb1.objects.exclude(name__icontains="ven") # range models.Tb1.objects.filter(id__range=[1, 2]) # 范围bettwen and # 其他类似 #startswith,istartswith, endswith, iendswith, # order by models.Tb1.objects.filter(name=‘seven‘).order_by(‘id‘) # asc models.Tb1.objects.filter(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] # regex正则匹配,iregex 不区分大小写 models.Entry.objects.get(title__regex=r‘^(An?|The) +‘) models.Entry.objects.get(title__iregex=r‘^(an?|the) +‘) # date import datetime models.Entry.objects.filter(pub_date__date=datetime.date(2005, 1, 1)) models.Entry.objects.filter(pub_date__date__gt=datetime.date(2005, 1, 1)) # year models.Entry.objects.filter(pub_date__year=2005) models.Entry.objects.filter(pub_date__year__gte=2005) # month models.Entry.objects.filter(pub_date__month=12) models.Entry.objects.filter(pub_date__month__gte=6) # day models.Entry.objects.filter(pub_date__day=3) models.Entry.objects.filter(pub_date__day__gte=3) # week_day models.Entry.objects.filter(pub_date__week_day=2) models.Entry.objects.filter(pub_date__week_day__gte=2) # hour models.Event.objects.filter(timestamp__hour=23) models.Event.objects.filter(time__hour=5) models.Event.objects.filter(timestamp__hour__gte=12) # minute models.Event.objects.filter(timestamp__minute=29) models.Event.objects.filter(time__minute=46) models.Event.objects.filter(timestamp__minute__gte=29) # second models.Event.objects.filter(timestamp__second=31) models.Event.objects.filter(time__second=2) models.Event.objects.filter(timestamp__second__gte=31)
ORM高级操作(Q,F,extra,原生SQL)
#extra #extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None) models.Entry.objects.extra(select={‘new_id‘: "select col from sometable where othercol > %s"}, select_params=(1,)) #select *,(select col from sometable where otherco >1) as new_id from Entry models.Entry.objects.extra(where=[‘headline=%s‘], params=[‘Lennon‘]) #select * from Entry where headline=‘Lennon‘ models.Entry.objects.extra(where=["foo=‘a‘ OR bar = ‘a‘", "baz = ‘a‘"]) #select * from Entry where foo=‘a‘ or bar = ‘a‘ and baz=‘a‘ models.Entry.objects.extra(select={‘new_id‘: "select id from tb where id > %s"}, select_params=(1,), order_by=[‘-nid‘]) #select *,(select id from tb where id > 1) from Entry order nid desc #F from django.db.models import F models.Tb1.objects.update(num=F(‘num‘)+1) #先引用(F(‘num‘)+1 用来将原始值取出并+1),再赋值(num=F(‘num‘)+1)相当于,num+1之后更新 #Q from django.db.models import Q #方式一: Q(nid__gt=10) #where nid > 10 Q(nid=8) | Q(nid__gt=10) #where nid =8 or nid >10 Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption=‘root‘) # 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)) # q1 : where id =1 or id=10 or id=9 q2 = Q() q2.connector = ‘OR‘ q2.children.append((‘c1‘, 1)) q2.children.append((‘c1‘, 10)) q2.children.append((‘c1‘, 9)) #q2 :where c1=1 or c1=10 or c1=9 con.add(q1, ‘AND‘) con.add(q2, ‘AND‘) #con: where (id =1 or id=10 or id=9 ) and (c1=1 or c1=10 or c1=9) 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() #拿到默认数据库default连接的游标 cursors = connections[‘db1‘].cursor() #拿到指定数据库db1的游标 cursor.execute("""SELECT * from auth_user where id = %s""", [1]) row = cursor.fetchone()
ORM其他操作(ORM对象方法拆解)
################################################################## # PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET # ################################################################## def all(self) # 获取所有的数据对象 def filter(self, *args, **kwargs) # 条件查询 # 条件可以是:参数,字典,Q def exclude(self, *args, **kwargs) # 条件查询 # 条件可以是:参数,字典,Q def select_related(self, *fields) 性能相关:表之间进行join连表操作,一次性获取关联的数据。 model.tb.objects.all().select_related() model.tb.objects.all().select_related(‘外键字段‘) model.tb.objects.all().select_related(‘外键字段__外键字段‘) def prefetch_related(self, *lookups) 性能相关:多表连表操作时速度会慢,使用其执行多次SQL查询在Python代码中实现连表操作。 # 获取所有用户表 # 获取用户类型表where id in (用户表中的查到的所有用户ID) models.UserInfo.objects.prefetch_related(‘外键字段‘) from django.db.models import Count, Case, When, IntegerField Article.objects.annotate( numviews=Count(Case( When(readership__what_time__lt=treshold, then=1), output_field=CharField(), )) ) students = Student.objects.all().annotate(num_excused_absences=models.Sum( models.Case( models.When(absence__type=‘Excused‘, then=1), default=0, output_field=models.IntegerField() ))) def annotate(self, *args, **kwargs) # 用于实现聚合group by查询 from django.db.models import Count, Avg, Max, Min, Sum v = models.UserInfo.objects.values(‘u_id‘).annotate(uid=Count(‘u_id‘)) # SELECT u_id, COUNT(ui) AS `uid` FROM UserInfo GROUP BY u_id v = models.UserInfo.objects.values(‘u_id‘).annotate(uid=Count(‘u_id‘)).filter(uid__gt=1) # SELECT u_id, COUNT(ui_id) AS `uid` FROM UserInfo GROUP BY u_id having count(u_id) > 1 v = models.UserInfo.objects.values(‘u_id‘).annotate(uid=Count(‘u_id‘,distinct=True)).filter(uid__gt=1) # SELECT u_id, COUNT( DISTINCT ui_id) AS `uid` FROM UserInfo GROUP BY u_id having count(u_id) > 1 def distinct(self, *field_names) # 用于distinct去重 models.UserInfo.objects.values(‘nid‘).distinct() # select distinct nid from userinfo 注:只有在PostgreSQL中才能使用distinct进行去重 def order_by(self, *field_names) # 用于排序 models.UserInfo.objects.all().order_by(‘-id‘,‘age‘) def extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None) # 构造额外的查询条件或者映射,如:子查询 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‘]) def reverse(self): # 倒序 models.UserInfo.objects.all().order_by(‘-nid‘).reverse() # 注:如果存在order_by,reverse则是倒序,如果多个排序则一一倒序 def defer(self, *fields): models.UserInfo.objects.defer(‘username‘,‘id‘) 或 models.UserInfo.objects.filter(...).defer(‘username‘,‘id‘) #映射中排除某列数据 def only(self, *fields): #仅取某个表中的数据 models.UserInfo.objects.only(‘username‘,‘id‘) 或 models.UserInfo.objects.filter(...).only(‘username‘,‘id‘) def using(self, alias): 指定使用的数据库,参数为别名(setting中的设置) ################################################## # PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS # ################################################## def raw(self, raw_query, params=None, translations=None, using=None): # 执行原生SQL models.UserInfo.objects.raw(‘select * from userinfo‘) # 如果SQL是其他表时,必须将名字设置为当前UserInfo对象的主键列名 models.UserInfo.objects.raw(‘select id as nid from 其他表‘) # 为原生SQL设置参数 models.UserInfo.objects.raw(‘select id as nid from userinfo where nid>%s‘, params=[12,]) # 将获取的到列名转换为指定列名 name_map = {‘first‘: ‘first_name‘, ‘last‘: ‘last_name‘, ‘bd‘: ‘birth_date‘, ‘pk‘: ‘id‘} Person.objects.raw(‘SELECT * FROM some_other_table‘, translations=name_map) # 指定数据库 models.UserInfo.objects.raw(‘select * from userinfo‘, using="default") ################### 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() # fetchall()/fetchmany(..) def values(self, *fields): # 获取每行数据为字典格式 def values_list(self, *fields, **kwargs): # 获取每行数据为元祖 def dates(self, field_name, kind, order=‘ASC‘): # 根据时间进行某一部分进行去重查找并截取指定内容 # kind只能是:"year"(年), "month"(年-月), "day"(年-月-日) # order只能是:"ASC" "DESC" # 并获取转换后的时间 - year : 年-01-01 - month: 年-月-01 - day : 年-月-日 models.DatePlus.objects.dates(‘ctime‘,‘day‘,‘DESC‘) def datetimes(self, field_name, kind, order=‘ASC‘, tzinfo=None): # 根据时间进行某一部分进行去重查找并截取指定内容,将时间转换为指定时区时间 # kind只能是 "year", "month", "day", "hour", "minute", "second" # order只能是:"ASC" "DESC" # tzinfo时区对象 models.DDD.objects.datetimes(‘ctime‘,‘hour‘,tzinfo=pytz.UTC) models.DDD.objects.datetimes(‘ctime‘,‘hour‘,tzinfo=pytz.timezone(‘Asia/Shanghai‘)) """ pip3 install pytz import pytz pytz.all_timezones pytz.timezone(‘Asia/Shanghai’) """ def none(self): # 空QuerySet对象 #################################### # METHODS THAT DO DATABASE QUERIES # #################################### def aggregate(self, *args, **kwargs): # 聚合函数,获取字典类型聚合结果 from django.db.models import Count, Avg, Max, Min, Sum result = models.UserInfo.objects.aggregate(k=Count(‘u_id‘, distinct=True), n=Count(‘nid‘)) ===> {‘k‘: 3, ‘n‘: 4} def count(self): # 获取个数 def get(self, *args, **kwargs): # 获取单个对象 def create(self, **kwargs): # 创建对象 def bulk_create(self, objs, batch_size=None): # 批量插入 # batch_size表示一次插入的个数 objs = [ models.DDD(name=‘r11‘), models.DDD(name=‘r22‘) ] models.DDD.objects.bulk_create(objs, 10) def get_or_create(self, defaults=None, **kwargs): # 如果存在,则获取,否则,创建 # defaults 指定创建时,其他字段的值 obj, created = models.UserInfo.objects.get_or_create(username=‘root1‘, defaults={‘email‘: ‘1111111‘,‘u_id‘: 2, ‘t_id‘: 2}) def update_or_create(self, defaults=None, **kwargs): # 如果存在,则更新,否则,创建 # defaults 指定创建时或更新时的其他字段 obj, created = models.UserInfo.objects.update_or_create(username=‘root1‘, defaults={‘email‘: ‘1111111‘,‘u_id‘: 2, ‘t_id‘: 1}) def first(self): # 获取第一个 def last(self): # 获取最后一个 def in_bulk(self, id_list=None): # 根据主键ID进行查找 id_list = [11,21,31] models.DDD.objects.in_bulk(id_list) def delete(self): # 删除 def update(self, **kwargs): # 更新 def exists(self): # 是否有结果
ORM连表查询操作:
# 每次循环连表查询 # restea = models.teac_clas.objects.filter(teachers_id__tName="武沛齐") # for i in restea: # print(i.teachers_id.tName) #使用values方法直接获取字典无需循环连表 # restea = models.teac_clas.objects.filter(teachers_id__tName="武沛齐").values("teachers_id__tName") # for i in restea: # print(i["teachers_id__tName"])
ORM连表示例:
class Boy(models.Model): bname = models.CharField(max_length=10) class Girl(models.Model): gname = models.CharField(max_length=10) class b_g(models.Model): b = models.ForeignKey("Boy") g = models.ForeignKey("Girl") class Mate: unique_bj=[("b","g")] #唯一索引(男生和女生只能唯一匹配)
# 编辑者:闫龙 from django.views import View from django.shortcuts import HttpResponse from appOne import models class TestView(View): def addData(self): girllist=[ models.Girl(gname="小爽"), models.Girl(gname="小红"), models.Girl(gname="小黄"), models.Girl(gname="小白"), ] boylist=[ models.Boy(bname="龙哥"), models.Boy(bname="小明"), models.Boy(bname="小齐"), models.Boy(bname="小杰"), ] models.Girl.objects.bulk_create(girllist) models.Boy.objects.bulk_create(boylist) def get(self,request): #通过关系表,双下划线到boy中获取名称,在通过双下划线到girl中拿到相应的值 #res = models.b_g.objects.filter(b_id__bname="龙哥").values("g_id__gname") # for i in res: # print(i["g_id__gname"]) #通过关系表,双下划綫到boy中获取名称,在通过girl对象索引到相应的值 res = models.b_g.objects.filter(b_id__bname="龙哥") for i in res: print(i.g.gname)#i.g获取girl对象,拿到相应的名字 return HttpResponse(".....")
ORM关系表:
from appTwo import models from django.views import View from django.shortcuts import HttpResponse class TestView(View): def addData(self): girllist=[ models.girls(gname="小爽"), models.girls(gname="小红"), models.girls(gname="小黄"), models.girls(gname="小白"), ] boylist=[ models.boys(bname="龙哥"), models.boys(bname="小明"), models.boys(bname="小齐"), models.boys(bname="小杰"), ] models.Girl.objects.bulk_create(girllist) models.Boy.objects.bulk_create(boylist) def get(self,request): res = models.boys.objects.filter(bname="龙哥").first() girllist = res.bAg.all() #拿到res.id对应在boys_bAg中,对应girl的所有对象 for i in girllist: print(i.gname) res.bAg.add(4) #向boys_bAg中加入res.id , 4数据等同于insert into boys_bAg(boys_id,girls_id) values(1,4) res.bAg.remove(2) #删除boys_bAg中boys_id=res.id and girls_id = 2的数据 res.bAg.set(2) #清空boys_bAg中所有boys_id=res.id的数据,并插入数据boys_id=res.id,girls_id=2 res.bAg.clear() #清空boys_bAg中所有boys_id=res.id的数据 return HttpResponse("......")
数据库操作
数据库操作 class UserGroup(models.Model): """ 部门 3 """ title = models.CharField(max_length=32) class UserInfo(models.Model): """ 员工4 """ nid = models.BigAutoField(primary_key=True) user = models.CharField(max_length=32) password = models.CharField(max_length=64) age = models.IntegerField(default=1) # ug_id 1 ug = models.ForeignKey("UserGroup",null=True) - 跨表 正: 1. q = UserInfo.objects.all().first() q.ug.title 2. UserInfo.objects.values(‘nid‘,‘ug_id‘) UserInfo.objects.values(‘nid‘,‘ug_id‘,‘ug__title‘) 3. UserInfo.objects.values_list(‘nid‘,‘ug_id‘,‘ug__title‘) 反: 1. 小写的表名_set obj = UserGroup.objects.all().first() result = obj.userinfo_set.all() [userinfo对象,userinfo对象,] 2. 小写的表名 v = UserGroup.objects.values(‘id‘,‘title‘) v = UserGroup.objects.values(‘id‘,‘title‘,‘小写的表名称‘) v = UserGroup.objects.values(‘id‘,‘title‘,‘小写的表名称__age‘) 3. 小写的表名 v = UserGroup.objects.values_list(‘id‘,‘title‘) v = UserGroup.objects.values_list(‘id‘,‘title‘,‘小写的表名称‘) v = UserGroup.objects.values_list(‘id‘,‘title‘,‘小写的表名称__age‘) PS: 前面的所有数据都会显示 - 其他: UserInfo.objects.all() UserInfo.objects.filter(id=1,id=2) UserInfo.objects.all().first() UserInfo.objects.all().count() UserInfo.objects.all().update() UserInfo.objects.all().delete() UserInfo.objects.all()[1:19] 跨表: 正向: xxxx.filter(ut__title=‘超级用户‘).values(‘id‘,‘name‘,‘ut__title‘) 反向: xxxx.filter(表名称__title=‘超级用户‘).values(‘id‘,‘name‘,‘表名称__title‘)
ORM操作补
Django ORM操作 # 1.增删改查 # 2. 一般: # models.UserInfo.objects.filter(id__gt=1) # models.UserInfo.objects.filter(id__lt=1) # models.UserInfo.objects.filter(id__lte=1) # models.UserInfo.objects.filter(id__gte=1) # models.UserInfo.objects.filter(id__in=[1,2,3]) # models.UserInfo.objects.filter(id__range=[1,2]) # models.UserInfo.objects.filter(name__startswith=‘xxxx‘) # models.UserInfo.objects.filter(name__contains=‘xxxx‘) # models.UserInfo.objects.exclude(id=1) # 3. 排序 user_list = models.UserInfo.objects.all().order_by(‘-id‘,‘name‘) # 4. 分组 annotate ,group by ,加filter相当于having from django.db.models import Count,Sum,Max,Min # v =models.UserInfo.objects.values(‘ut_id‘).annotate(xxxx=Count(‘id‘)) # print(v.query) # v =models.UserInfo.objects.values(‘ut_id‘).annotate(xxxx=Count(‘id‘)).filter(xxxx__gt=2) # print(v.query) # v =models.UserInfo.objects.filter(id__gt=2).values(‘ut_id‘).annotate(xxxx=Count(‘id‘)).filter(xxxx__gt=2) # print(v.query) # 5. F,更新时用于获取原来的值 # from django.db.models import F,Q # models.UserInfo.objects.all().update(age=F("age")+1) # 6. Q,用于构造复杂查询条件 # 应用一: # models.UserInfo.objects.filter(Q(id__gt=1)) # models.UserInfo.objects.filter(Q(id=8) | Q(id=2)) # models.UserInfo.objects.filter(Q(id=8) & Q(id=2)) # 应用二: # q1 = Q() # q1.connector = ‘OR‘ # q1.children.append((‘id__gt‘, 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)) # # q3 = Q() # q3.connector = ‘AND‘ # q3.children.append((‘id‘, 1)) # q3.children.append((‘id‘, 2)) # q2.add(q3,‘OR‘) # # con = Q() # con.add(q1, ‘AND‘) # con.add(q2, ‘AND‘) # models.UserInfo.objects.filter(con) # 7. extra, 额外查询条件以及相关表,排序 models.UserInfo.objects.filter(id__gt=1) models.UserInfo.objects.all() # id name age ut_id models.UserInfo.objects.extra(self, select=None, where=None, params=None, tables=None, order_by=None, select_params=None) # a. 映射 # select # select_params=None # select 此处 from 表 # b. 条件 # where=None # params=None, # select * from 表 where 此处 # c. 表 # tables # select * from 表,此处 # c. 排序 # order_by=None # select * from 表 order by 此处 models.UserInfo.objects.extra( select={‘newid‘:‘select count(1) from app01_usertype where id>%s‘}, select_params=[1,], where = [‘age>%s‘], params=[18,], order_by=[‘-age‘], tables=[‘app01_usertype‘] ) """ select app01_userinfo.id, (select count(1) from app01_usertype where id>1) as newid from app01_userinfo,app01_usertype where app01_userinfo.age > 18 order by app01_userinfo.age desc """ result = models.UserInfo.objects.filter(id__gt=1).extra( where=[‘app01_userinfo.id < %s‘], params=[100,], tables=[‘app01_usertype‘], order_by=[‘-app01_userinfo.id‘], select={‘uid‘:1,‘sw‘:"select count(1) from app01_userinfo"} ) print(result.query) # SELECT (1) AS "uid", (select count(1) from app01_userinfo) AS "sw", "app01_userinfo"."id", "app01_userinfo"."name", "app01_userinfo"."age", "app01_userinfo"."ut_id" FROM "app01_userinfo" , "app01_usertype" WHERE ("app01_userinfo"."id" > 1 AND (app01_userinfo.id < 100)) ORDER BY ("app01_userinfo".id) DESC # 8. 原生SQL语句 from django.db import connection, connections cursor = connection.cursor() # connection=default数据 cursor = connections[‘db2‘].cursor() cursor.execute("""SELECT * from auth_user where id = %s""", [1]) row = cursor.fetchone() row = cursor.fetchall() - extra - 原生SQL语句 - raw result = models.UserInfo.objects.raw(‘select * from userinfo‘) [obj(UserInfo),obj,] result = models.UserInfo.objects.raw(‘select id,1 as name,2 as age,4 as ut_id from usertype‘) [obj(UserInfo),obj,] v1 = models.UserInfo.objects.raw(‘SELECT id,title FROM app01_usertype‘,translations=name_map) # 9. 简单的操作 http://www.cnblogs.com/wupeiqi/articles/6216618.html
Model
AutoField(Field) - int自增列,必须填入参数 primary_key=True BigAutoField(AutoField) - bigint自增列,必须填入参数 primary_key=True 注:当model中如果没有自增列,则自动会创建一个列名为id的列 from django.db import models class UserInfo(models.Model): # 自动创建一个列名为id的且为自增的整数列 username = models.CharField(max_length=32) class Group(models.Model): # 自定义自增列 nid = models.AutoField(primary_key=True) name = models.CharField(max_length=32) SmallIntegerField(IntegerField): - 小整数 -32768 ~ 32767 PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField) - 正小整数 0 ~ 32767 IntegerField(Field) - 整数列(有符号的) -2147483648 ~ 2147483647 PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField) - 正整数 0 ~ 2147483647 BigIntegerField(IntegerField): - 长整型(有符号的) -9223372036854775808 ~ 9223372036854775807 BooleanField(Field) - 布尔值类型 NullBooleanField(Field): - 可以为空的布尔值 CharField(Field) - 字符类型 - 必须提供max_length参数, max_length表示字符长度 TextField(Field) - 文本类型 EmailField(CharField): - 字符串类型,Django Admin以及ModelForm中提供验证机制 IPAddressField(Field) - 字符串类型,Django Admin以及ModelForm中提供验证 IPV4 机制 GenericIPAddressField(Field) - 字符串类型,Django Admin以及ModelForm中提供验证 Ipv4和Ipv6 - 参数: protocol,用于指定Ipv4或Ipv6, ‘both‘,"ipv4","ipv6" unpack_ipv4, 如果指定为True,则输入::ffff:192.0.2.1时候,可解析为192.0.2.1,开启刺功能,需要protocol="both" URLField(CharField) - 字符串类型,Django Admin以及ModelForm中提供验证 URL SlugField(CharField) - 字符串类型,Django Admin以及ModelForm中提供验证支持 字母、数字、下划线、连接符(减号) CommaSeparatedIntegerField(CharField) - 字符串类型,格式必须为逗号分割的数字 UUIDField(Field) - 字符串类型,Django Admin以及ModelForm中提供对UUID格式的验证 FilePathField(Field) - 字符串,Django Admin以及ModelForm中提供读取文件夹下文件的功能 - 参数: path, 文件夹路径 match=None, 正则匹配 recursive=False, 递归下面的文件夹 allow_files=True, 允许文件 allow_folders=False, 允许文件夹 FileField(Field) - 字符串,路径保存在数据库,文件上传到指定目录 - 参数: upload_to = "" 上传文件的保存路径 storage = None 存储组件,默认django.core.files.storage.FileSystemStorage ImageField(FileField) - 字符串,路径保存在数据库,文件上传到指定目录 - 参数: upload_to = "" 上传文件的保存路径 storage = None 存储组件,默认django.core.files.storage.FileSystemStorage width_field=None, 上传图片的高度保存的数据库字段名(字符串) height_field=None 上传图片的宽度保存的数据库字段名(字符串) DateTimeField(DateField) - 日期+时间格式 YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] DateField(DateTimeCheckMixin, Field) - 日期格式 YYYY-MM-DD TimeField(DateTimeCheckMixin, Field) - 时间格式 HH:MM[:ss[.uuuuuu]] DurationField(Field) - 长整数,时间间隔,数据库中按照bigint存储,ORM中获取的值为datetime.timedelta类型 FloatField(Field) - 浮点型 DecimalField(Field) - 10进制小数 - 参数: max_digits,小数总长度 decimal_places,小数位长度 BinaryField(Field) - 二进制类型
class UnsignedIntegerField(models.IntegerField): def db_type(self, connection): return ‘integer UNSIGNED‘ PS: 返回值为字段在数据库中的属性,Django字段默认的值为: ‘AutoField‘: ‘integer AUTO_INCREMENT‘, ‘BigAutoField‘: ‘bigint AUTO_INCREMENT‘, ‘BinaryField‘: ‘longblob‘, ‘BooleanField‘: ‘bool‘, ‘CharField‘: ‘varchar(%(max_length)s)‘, ‘CommaSeparatedIntegerField‘: ‘varchar(%(max_length)s)‘, ‘DateField‘: ‘date‘, ‘DateTimeField‘: ‘datetime‘, ‘DecimalField‘: ‘numeric(%(max_digits)s, %(decimal_places)s)‘, ‘DurationField‘: ‘bigint‘, ‘FileField‘: ‘varchar(%(max_length)s)‘, ‘FilePathField‘: ‘varchar(%(max_length)s)‘, ‘FloatField‘: ‘double precision‘, ‘IntegerField‘: ‘integer‘, ‘BigIntegerField‘: ‘bigint‘, ‘IPAddressField‘: ‘char(15)‘, ‘GenericIPAddressField‘: ‘char(39)‘, ‘NullBooleanField‘: ‘bool‘, ‘OneToOneField‘: ‘integer‘, ‘PositiveIntegerField‘: ‘integer UNSIGNED‘, ‘PositiveSmallIntegerField‘: ‘smallint UNSIGNED‘, ‘SlugField‘: ‘varchar(%(max_length)s)‘, ‘SmallIntegerField‘: ‘smallint‘, ‘TextField‘: ‘longtext‘, ‘TimeField‘: ‘time‘, ‘UUIDField‘: ‘char(32)‘,
1.触发Model中的验证和错误提示有两种方式: a. Django Admin中的错误信息会优先根据Admiin内部的ModelForm错误信息提示,如果都成功,才来检查Model的字段并显示指定错误信息 b. 使用ModelForm c. 调用Model对象的 clean_fields 方法,如: # models.py class UserInfo(models.Model): nid = models.AutoField(primary_key=True) username = models.CharField(max_length=32) email = models.EmailField(error_messages={‘invalid‘: ‘格式错了.‘}) # views.py def index(request): obj = models.UserInfo(username=‘11234‘, email=‘uu‘) try: print(obj.clean_fields()) except Exception as e: print(e) return HttpResponse(‘ok‘) # Model的clean方法是一个钩子,可用于定制操作,如:上述的异常处理。 2.Admin中修改错误提示 # admin.py from django.contrib import admin from model_club import models from django import forms class UserInfoForm(forms.ModelForm): age = forms.IntegerField(initial=1, error_messages={‘required‘: ‘请输入数值.‘, ‘invalid‘: ‘年龄必须为数值.‘}) class Meta: model = models.UserInfo # fields = (‘username‘,) fields = "__all__" exclude = [‘title‘] labels = { ‘name‘:‘Writer‘, } help_texts = {‘name‘:‘some useful help text.‘,} error_messages={ ‘name‘:{‘max_length‘:"this writer name is too long"} } widgets={‘name‘:Textarea(attrs={‘cols‘:80,‘rows‘:20})} class UserInfoAdmin(admin.ModelAdmin): form = UserInfoForm admin.site.register(models.UserInfo, UserInfoAdmin)
null 数据库中字段是否可以为空 db_column 数据库中字段的列名 default 数据库中字段的默认值 primary_key 数据库中字段是否为主键 db_index 数据库中字段是否可以建立索引 unique 数据库中字段是否可以建立唯一索引 unique_for_date 数据库中字段【日期】部分是否可以建立唯一索引 unique_for_month 数据库中字段【月】部分是否可以建立唯一索引 unique_for_year 数据库中字段【年】部分是否可以建立唯一索引 verbose_name Admin中显示的字段名称 blank Admin中是否允许用户输入为空 editable Admin中是否可以编辑 help_text Admin中该字段的提示信息 choices Admin中显示选择框的内容,用不变动的数据放在内存中从而避免跨表操作 如:gf = models.IntegerField(choices=[(0, ‘何穗‘),(1, ‘大表姐‘),],default=1) error_messages 自定义错误信息(字典类型),从而定制想要显示的错误信息; 字典健:null, blank, invalid, invalid_choice, unique, and unique_for_date 如:{‘null‘: "不能为空.", ‘invalid‘: ‘格式错误‘} validators 自定义错误验证(列表类型),从而定制想要的验证规则 from django.core.validators import RegexValidator from django.core.validators import EmailValidator,URLValidator,DecimalValidator, MaxLengthValidator,MinLengthValidator,MaxValueValidator,MinValueValidator 如: test = models.CharField( max_length=32, error_messages={ ‘c1‘: ‘优先错信息1‘, ‘c2‘: ‘优先错信息2‘, ‘c3‘: ‘优先错信息3‘, }, validators=[ RegexValidator(regex=‘root_\d+‘, message=‘错误了‘, code=‘c1‘), RegexValidator(regex=‘root_112233\d+‘, message=‘又错误了‘, code=‘c2‘), EmailValidator(message=‘又错误了‘, code=‘c3‘), ] )
class UserInfo(models.Model): nid = models.AutoField(primary_key=True) username = models.CharField(max_length=32) class Meta: # 数据库中生成的表名称 默认 app名称 + 下划线 + 类名 db_table = "table_name" # 联合索引 index_together = [ ("pub_date", "deadline"), ] # 联合唯一索引 unique_together = (("driver", "restaurant"),) # admin中显示的表名称 verbose_name # verbose_name加s verbose_name_plural
ForeignKey(ForeignObject) # ForeignObject(RelatedField) to, # 要进行关联的表名 to_field=None, # 要关联的表中的字段名称 on_delete=None, # 当删除关联表中的数据时,当前表与其关联的行的行为 - models.CASCADE,删除关联数据,与之关联也删除 - models.DO_NOTHING,删除关联数据,引发错误IntegrityError - models.PROTECT,删除关联数据,引发错误ProtectedError - models.SET_NULL,删除关联数据,与之关联的值设置为null(前提FK字段需要设置为可空) - models.SET_DEFAULT,删除关联数据,与之关联的值设置为默认值(前提FK字段需要设置默认值) - models.SET,删除关联数据, a. 与之关联的值设置为指定值,设置:models.SET(值) b. 与之关联的值设置为可执行对象的返回值,设置:models.SET(可执行对象) def func(): return 10 class MyModel(models.Model): user = models.ForeignKey( to="User", to_field="id" on_delete=models.SET(func),) related_name=None, # 反向操作时,使用的字段名,用于代替 【表名_set】 如: obj.表名_set.all() related_query_name=None, # 反向操作时,使用的连接前缀,用于替换【表名】 如: models.UserGroup.objects.filter(表名__字段名=1).values(‘表名__字段名‘) limit_choices_to=None, # 在Admin或ModelForm中显示关联数据时,提供的条件: # 如: - limit_choices_to={‘nid__gt‘: 5} - limit_choices_to=lambda : {‘nid__gt‘: 5} from django.db.models import Q - limit_choices_to=Q(nid__gt=10) - limit_choices_to=Q(nid=8) | Q(nid__gt=10) - limit_choices_to=lambda : Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption=‘root‘) db_constraint=True # 是否在数据库中创建外键约束 parent_link=False # 在Admin中是否显示关联数据 OneToOneField(ForeignKey) to, # 要进行关联的表名 to_field=None # 要关联的表中的字段名称 on_delete=None, # 当删除关联表中的数据时,当前表与其关联的行的行为 ###### 对于一对一 ###### # 1. 一对一其实就是 一对多 + 唯一索引 # 2.当两个类之间有继承关系时,默认会创建一个一对一字段 # 如下会在A表中额外增加一个c_ptr_id列且唯一: class C(models.Model): nid = models.AutoField(primary_key=True) part = models.CharField(max_length=12) class A(C): id = models.AutoField(primary_key=True) code = models.CharField(max_length=1) ManyToManyField(RelatedField) to, # 要进行关联的表名 related_name=None, # 反向操作时,使用的字段名,用于代替 【表名_set】 如: obj.表名_set.all() related_query_name=None, # 反向操作时,使用的连接前缀,用于替换【表名】 如: models.UserGroup.objects.filter(表名__字段名=1).values(‘表名__字段名‘) limit_choices_to=None, # 在Admin或ModelForm中显示关联数据时,提供的条件: # 如: - limit_choices_to={‘nid__gt‘: 5} - limit_choices_to=lambda : {‘nid__gt‘: 5} from django.db.models import Q - limit_choices_to=Q(nid__gt=10) - limit_choices_to=Q(nid=8) | Q(nid__gt=10) - limit_choices_to=lambda : Q(Q(nid=8) | Q(nid__gt=10)) & Q(caption=‘root‘) symmetrical=None, # 仅用于多对多自关联时,symmetrical用于指定内部是否创建反向操作的字段 # 做如下操作时,不同的symmetrical会有不同的可选字段 models.BB.objects.filter(...) # 可选字段有:code, id, m1 class BB(models.Model): code = models.CharField(max_length=12) m1 = models.ManyToManyField(‘self‘,symmetrical=True) # 可选字段有: bb, code, id, m1 class BB(models.Model): code = models.CharField(max_length=12) m1 = models.ManyToManyField(‘self‘,symmetrical=False) through=None, # 自定义第三张表时,使用字段用于指定关系表 through_fields=None, # 自定义第三张表时,使用字段用于指定关系表中那些字段做多对多关系表 from django.db import models class Person(models.Model): name = models.CharField(max_length=50) class Group(models.Model): name = models.CharField(max_length=128) members = models.ManyToManyField( Person, through=‘Membership‘, through_fields=(‘group‘, ‘person‘), ) class Membership(models.Model): group = models.ForeignKey(Group, on_delete=models.CASCADE) person = models.ForeignKey(Person, on_delete=models.CASCADE) inviter = models.ForeignKey( Person, on_delete=models.CASCADE, related_name="membership_invites", ) invite_reason = models.CharField(max_length=64) db_constraint=True, # 是否在数据库中创建外键约束 db_table=None, # 默认创建第三张表时,数据库中表的名称
标签:http 连接 exception class 无符号 唯一索引 查找 cond unique
原文地址:http://www.cnblogs.com/fortunate/p/7109345.html