django_demo/orm_demo/orm_crud.py

from orm_demo.models import *
from django.db.models import F, Q, Count
from django.db import connection

# 插入数据
# 先实例化对象，然后为对象赋值
depart_data = DepartInfo()
depart_data.depart_name = '开发部'
depart_data.save()

# 实例化对象同时赋值
skill_data = SkillInfo(skill_name='PHP')
skill_data.save()

# create方法赋值
user = BaseUserInfo.objects.create(username='张三', password='zhangsan', status=1)

# create方式赋值， 字典格式数据
data = {'username': '李四', 'password': 'lisi', 'status': 1}
# data2 = dict(username='李四', password='lisi', status=1)  # 另一种字典数据定义形势
user2 = BaseUserInfo.objects.create(**data)

# 批量插入
data_list = [
    {'username': '王五', 'password': 'wangwu', 'status': 1},
    {'username': '孙六', 'password': 'sunliu', 'status': 1}
]
user_obj_list = []
for data in data_list:
    user_obj = BaseUserInfo(username=data['username'], password=data['password'], status=data['status'])
    user_obj_list.append(user_obj)
users = BaseUserInfo.objects.bulk_create(user_obj_list)

# 插入外键关联的数据
user1 = BaseUserInfo.objects.filter(username='张三').first()
department1 = DepartInfo.objects.filter(depart_name='开发部').first()
user_e1 = UserExtendInfo(username='张三', true_name='张三丰', sex=1, age=33, department='开发部', salary='230000.00',
                         status=1, memo='', user=user1, depart=department1)
user_e1.save()

# 插入ManyToMany字段数据add()和set()
skill_php = SkillInfo.objects.filter(skill_name='PHP').first()
user_zhang = UserExtendInfo.objects.filter(username='张三').first()
skill_php.user.add(user_zhang)  # 使用add方法添加外键关联关系

# 一次建立多个连接关系
skill_py = SkillInfo.objects.filter(skill_name='Python').first()
user_zhang = UserExtendInfo.objects.filter(username='张三').first()
user_sun = UserExtendInfo.objects.filter(username='孙六').first()
skill_py.user.add(user_zhang, user_sun)  # add方法可以添加多个关联关系

# 直接创建关联关系数据
skill_draw = SkillInfo.objects.filter(skill_name='draw').first()
user_zhou = BaseUserInfo.objects.filter(username='周七').first()
depart_zhou = DepartInfo.objects.filter(depart_name='设计部').first()
skill_draw.user.create(username='周七', true_name='周七天', sex=0, age=18, department='设计部', salary='8500.00',
                       status=1, memo='', user=user_zhou, depart=depart_zhou)

# 使用set修改关联数据
user_design = UserExtendInfo.objects.filter(department='设计部').all()
skill_ps = SkillInfo.objects.get(skill_name='Photoshop')
skill_ps.user.set(user_design)

# 直接给定id
skill_draw = SkillInfo.objects.get(skill_name='draw')
skill_draw.user.set([3])

# 批量关联多对多数据
skill_dev = SkillInfo.objects.filter(skill_name__in=['JavaScript', 'PHP']).all()
user_dev = UserExtendInfo.objects.filter(department='开发部').all()
for skill in skill_dev:
    skill.user.add(*user_dev)

# 更新数据
# 查询出结果后通过赋值方式使用save方法保存
skill_data = SkillInfo.objects.filter(skill_name='测试').first()
skill_data.skill_name = 'Test'
skill_data.save()

# 使用update方式直接修改
skill_data1 = SkillInfo.objects.filter(skill_name='画图').update(skill_name='draw')

# 删除数据 返回删除结果 (2, {'orm_demo.SkillInfo': 2})
SkillInfo.objects.create(skill_name='delete')
SkillInfo.objects.create(skill_name='delete')
del_skill = SkillInfo.objects.filter(skill_name='delete').delete()
print(del_skill)

# 关联表查询 一对一
# 通过扩展表名查询
user_li = BaseUserInfo.objects.filter(username='李四').first()
print(user_li.userextendinfo.true_name)  # 扩展表名需要小写， 返回：李四喜

# 通过关联字段查询
user_extend_li = UserExtendInfo.objects.filter(true_name__contains='李四').first()
print(user_extend_li.user.password)  # 使用关联字段名称， 返回：lisi

# 关联表查询 一对多
# 正向查询
user_zhang = BaseUserInfo.objects.get(id=1)
card_zhang = user_zhang.cardinfo_set.all()  # 使用小写的表名加上_set做为关联字段
for card in card_zhang:
    print(card.card_no)

# 正向查询 related_name 指定关联名称
user_zhang = BaseUserInfo.objects.get(id=1)
card_zhang = user_zhang.user_card.all()  # 使用指定的关联名做为关联字段
for card in card_zhang:
    print(card.card_no)

# 反向查询
card = CardInfo.objects.filter(user_id=1).first()
print(card.user.username)

# 多对多查询
# 正向查询
user_zhang = UserExtendInfo.objects.get(username='张三')
skill_user_zhang = user_zhang.skillinfo_set.all()
print(skill_user_zhang)

# 反向查询
skill_py = SkillInfo.objects.filter(skill_name='Python').first()
for user in skill_py.user.all():
    print(user.true_name)

# 多对多删除关联数据 remove clear
# 删除指定用户的指定技能
user_del = UserExtendInfo.objects.get(id=5)
skill_del = SkillInfo.objects.get(id=7)
result = skill_del.user.remove(user_del)
print(result)

# 通过id指定删除哪个用户
skill_del = SkillInfo.objects.get(id=1)
result = skill_del.user.remove(2)
print(result)

# 清除全部
skill_del = SkillInfo.objects.get(id=8)
result = skill_del.user.clear()
print(result)

# ForeignKey 直接获取关联表数据, 只能用在一对多设置外键的情况
card_data = CardInfo.objects.select_related('user')
for card in card_data:
    print(card.user)

# ManyToMany 多对多直接获取关联表数据
skill_data = SkillInfo.objects.prefetch_related('user')
for skill in skill_data:
    print(skill.skill_name)
    users = skill.user.all()
    for user in users:
        print(user.true_name)

# F()函数
users = UserExtendInfo.objects.all()
for user in users:
    user.salary = F('salary') + 1000
    user.save()
for user in users:
    user.refresh_from_db()
    print(user.salary)

# Q()函数 用于多条件查询
user = UserExtendInfo.objects.filter(Q(age__gt=30) & Q(salary__gt=10000)).first()
print(user.username)

# 执行原生SQL
users = UserExtendInfo.objects.raw("SELECT * FROM orm_user_base_info")
for user in users:
    print(type(user), user.username)

sql = "SELECT * FROM orm_user_extend_info WHERE age > %s and salary > %s"
users = UserExtendInfo.objects.raw(sql, [30, 10000])
for user in users:
    print(type(user), user.username)

# connect 游标
# 插入数据
import django.utils.timezone as timezone

time_now = timezone.now()
cursor = connection.cursor()
sql = "INSERT INTO orm_skill_info (skill_name, createDate) VALUES (%s, %s)"
cursor.execute(sql, ('selenium', time_now))
cursor.close()

# 查询数据
sql = "SELECT * FROM orm_user_extend_info"
cursor = connection.cursor()
cursor.execute(sql)
row = cursor.fetchone()
print(row)
cursor.close()

# 更新数据
cursor = connection.cursor()
try:
    update_sql = "UPDATE orm_depart_info SET depart_name = %s WHERE id = %s"
    data = ('开发部', 1)
    cursor.execute(update_sql, data)
    rowcount = cursor.rowcount
    print(rowcount)
    connection.commit()
except Exception as e:
    print(e)
    connection.rollback()
finally:
    cursor.close()

# 事务处理 transaction
from django.db import transaction


# 方式1：修饰器

@transaction.atomic
def trans(request):
    save_id = transaction.savepoint()  # 开启事件
    try:
        # somecode
        transaction.savepoint_commit(save_id)  # 提交事件
    except Exception as e:
        print(e)
        transaction.savepoint_rollback(save_id)  # 回滚事件


# 方式2： with语句

def trans_with(request):
    with transaction.atomic():
        save_id = transaction.savepoint()  # 开启事件
        try:
            # some code
            transaction.commit(save_id)  # 提交事件
        except Exception as e:
            print(e)
            transaction.rollback(save_id)  # 回滚事件


# 基本查询
# get 当查询结果多余一条时报错
user = BaseUserInfo.objects.get(id=2)
print(user)

# exclude 排除查询出来的数据
users = UserExtendInfo.objects.exclude(age__lt=30)
for user in users:
    print(user.true_name)

# filter 过滤数据
users = UserExtendInfo.objects.filter(Q(age__gte=30) & Q(department__in=['开发部', '测试部']))
for user in users:
    print(user.true_name)

# __gt __gte __lt __lte __in __contains  __year __month __day
users = BaseUserInfo.objects.filter(username__contains="孙")
for user in users:
    print(user)

users = BaseUserInfo.objects.filter(create_date__year='2023')
for user in users:
    print(user.create_date)

users = BaseUserInfo.objects.filter(create_date__day='08')
for user in users:
    print(user.create_date)

# values 用于指定显示具体字段
users = UserExtendInfo.objects.filter(username='张三').values('username', 'true_name', 'salary')
for user in users:
    print(user)
    print(user['true_name'])

# distinct 去重
departs = UserExtendInfo.objects.distinct().values('department')
for d in departs:
    print(d)

# 链式过滤器
users = UserExtendInfo.objects.filter(age__range=[20, 30]).exclude(salary__lt=17000)
for user in users:
    print(user.username)

# 结果切片
skills = SkillInfo.objects.all()[1:3]
print(skills)

# 排序 order_by
user_salary = UserExtendInfo.objects.order_by('salary').all()
for user in user_salary:
    print(user.salary)

# 排序 desc
user_salary = UserExtendInfo.objects.order_by(F('salary').desc())
for user in user_salary:
    print(user.salary)

# 排序 asc
user_salary = UserExtendInfo.objects.order_by(F('salary').asc())
for user in user_salary:
    print(user.salary)

# group_by query形式
users = UserExtendInfo.objects.all()
users.query.group_by = ['department']
for user in users:
    print(user.username, user.department)

# group_by aggregated count
users = UserExtendInfo.objects.values('username').aaggregate(count=Count('department'))
print(users)

# count


# sum

# UNION


# JOIN