一、django使用mysql数据库配置
# setting.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'HOST': '127.0.0.1', # 数据库服务ip地址
'PORT': '3306', # 数据库服务占用端口号
'NAME': 'django_t', # 库名
'USER': 'root', # 用户名
'PASSWORD': '123456', # 密码
'OPTIONS': {
'charset': 'utf8mb4', # 字符编码
},
}
}
二、在终端展示ORM转换的sql语句（日志配置）
# setting.py
LOGGING = {
'version': 1,
'disable_existing_loggers': False,
'handlers': {
'console':{
'level':'DEBUG',
'class':'logging.StreamHandler',
},
},
'loggers': {
'django.db.backends': {
'handlers': ['console'],
'propagate': True,
'level':'DEBUG',
},
}
}
三、创建一个模型类
开发环境
Python == 3.6.13
django == 2.2.24
mysqlclient == 2.0.3
Django项目初始化
python -m django startproject my_book_project （或 django-admin startproject my_book_project；建议使用前者，原因：如果有虚拟环境，避免系统环境存在django-admin导致虚拟环境调用脚本出错）
cd my_book_project
python manage.py startapp book
创建一个模型类
- book
- models.py
from django.db import models
class Book(models.Model):
id = models.AutoField(primary_key=True)
title = models.CharField(max_length=32)
state = models.BooleanField()
pub_date = models.DateField()
price = models.DecimalField(max_digits=8, decimal_places=2)
publish = models.CharField(max_length=32)
class Meta:
db_table = 'book_info' # 对表进行重命名，如果没有加这两行，表的名字为："app名_类名小写"
模型类字段与sql字段类型对应关系——django模型字段参考 ：https://docs.djangoproject.com/zh-hans/3.2/ref/models/fields/#autofield
把存在模型类的app注册到setting.py
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'book',
]
执行数据库迁移命令
python manage.py makemigrations
python manage.py migrate
查看book表创建语法
show create table book;
| book | CREATE TABLE `book` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`title` varchar(32) NOT NULL,
`state` tinyint(1) NOT NULL,
`pub_date` date NOT NULL,
`price` decimal(8,2) NOT NULL,
`publish` varchar(32) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 |
模型类对应sql
四、创建一个模型类调试接口
- my_book_project
- urls.py
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('', include('book.urls'))
]
- my_book_project
- book
- urls.py
from django.urls import path
from book import views
urlpatterns = [
path('book/', views.test_orm),
]
- my_book_project
- book
- views.py
from django.shortcuts import HttpResponse
def test_orm(request):
pass
五、使用ORM进行单表的增加操作
启动django服务
python manage.py runserver 8080
访问 http://127.0.0.1:8000/book/
方式1：插入一条书籍数据
from django.shortcuts import HttpResponse
from book.models import Book
def test_orm(request):
# book_obj = 主键值
book_obj = Book.objects.create(title="Django红宝书", state=True, price=100, publish="清华出版社", pub_date="2020-12-12") # 有返回值
return HttpResponse('ok')
查看控制台
(0.000) SELECT @@SQL_AUTO_IS_NULL; args=None
(0.000) SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; args=None
(0.002) INSERT INTO `book` (`title`, `state`, `pub_date`, `price`, `publish`) VALUES ('Django红宝书', 1, '2020-12-12', '100.00', '清华出版社'); args=['Django红宝书', True, '2020-12-12', '100.00', '清华出版社']
[06/Jul/2021 08:53:29] "GET /book/ HTTP/1.1" 200 2
方式2：插入一条书籍数据
from django.shortcuts import HttpResponse
from book.models import Book
def test_orm(request):
book_obj = Book(title="js红宝书", state=True, price=200, publish="北京出版社", pub_date="2020-11-11") # 没有返回值
book_obj.save()
return HttpResponse('ok')
查看控制台
(0.000) SELECT @@SQL_AUTO_IS_NULL; args=None
(0.000) SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; args=None
(0.001) INSERT INTO `book` (`title`, `state`, `pub_date`, `price`, `publish`) VALUES ('js红宝书', 1, '2020-11-11', '200.00', '北京出版社'); args=['js红宝书', True, '2020-11-11', '200.00', '北京出版社']
[06/Jul/2021 09:09:56] "GET /book/ HTTP/1.1" 200 2
六、使用ORM进行单表的查询操作
6.1、查询所有记录：
from django.shortcuts import HttpResponse
from book.models import Book
def test_orm(request):
book_obj = Book.objects.all()
print(f'查询表中所有的记录QuerySet:{book_obj}')
return HttpResponse('ok')
控制台
(0.000) SELECT @@SQL_AUTO_IS_NULL; args=None
(0.000) SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; args=None
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` LIMIT 21; args=()
[06/Jul/2021 09:19:29] "GET /book/ HTTP/1.1" 200 2
查询表中所有的记录QuerySet:<QuerySet [<Book: Book object (6)>, <Book: Book object (7)>]>
6.2、精准匹配查询
from django.shortcuts import HttpResponse
from book.models import Book
def test_orm(request):
book_obj = Book.objects.get(title='js红宝书') # 返回与所给筛选条件相匹配的对象，返回结果有且只有一个，如果符合筛选条件的对象超过一个或者没有都会抛出错误。
print(f'get方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title='Django红宝书') # 它包含了与所给筛选条件相匹配的对象
print(f'filter方法查询，QuerySet:{book_obj}')
return HttpResponse('ok')
控制台
get方法查询，QuerySet:Book object (6)
filter方法查询，QuerySet:<QuerySet [<Book: Book object (7)>]>
(0.000) SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; args=None
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` = 'js红宝书'; args=('js红宝书',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` = 'Django红宝书' LIMIT 21; args=('Django红宝书',)
[06/Jul/2021 09:29:35] "GET /book/ HTTP/1.1" 200 2
6.3、模糊匹配
import datetime
from django.shortcuts import HttpResponse
from book.models import Book
def test_orm(request):
book_obj = Book.objects.filter(price__in=[100, 200]) # IN
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(price__gt=100) # 大于 >
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(price__gte=100) # 大于等于 >=
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(price__lt=200) # 小于 <
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(price__lte=200) # 小于等于 <=
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(price__range=[100, 200]) # BETWEEN
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__contains="Django") # LIKE '%Django%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__icontains="django") # 不区分大小写 LIKE '%django%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__startswith="Django") # LIKE 'Django%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__istartswith="JS") # 不区分大小写 LIKE 'JS%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__endswith="红宝书") # LIKE 'Django%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__iendswith="红宝书") # 不区分大小写 LIKE 'JS%'
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date=datetime.date(2020, 12, 12)) # 日期精准匹配
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date__gte=datetime.date(2020, 12, 12)) # 日期大于等于某天
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date__year=2020) # 查询某年
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date__month=12) # 查询某月
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date__day=11) # 查询某天
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(pub_date__isnull=True) # isnull
print(f'filter方法查询，QuerySet:{book_obj}')
book_obj = Book.objects.filter(title__regex='^j') # regex
print(f'filter方法查询，QuerySet:{book_obj}')
return HttpResponse('ok')
控制台
(0.000) SELECT @@SQL_AUTO_IS_NULL; args=None
(0.000) SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED; args=None
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` IN (100, 200) LIMIT 21; args=(Decimal('100'), Decimal('200'))
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` > 100 LIMIT 21; args=(Decimal('100'),)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` >= 100 LIMIT 21; args=(Decimal('100'),)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` < 200 LIMIT 21; args=(Decimal('200'),)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` <= 200 LIMIT 21; args=(Decimal('200'),)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`price` BETWEEN 100 AND 200 LIMIT 21; args=(Decimal('100'), Decimal('200'))
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE BINARY '%Django%' LIMIT 21; args=('%Django%',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE '%django%' LIMIT 21; args=('%django%',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE BINARY 'Django%' LIMIT 21; args=('Django%',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE 'JS%' LIMIT 21; args=('JS%',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE BINARY '%红宝书' LIMIT 21; args=('%红宝书',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` LIKE '%红宝书' LIMIT 21; args=('%红宝书',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`pub_date` = '2020-12-12' LIMIT 21; args=('2020-12-12',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`pub_date` >= '2020-12-12' LIMIT 21; args=('2020-12-12',)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`pub_date` BETWEEN '2020-01-01' AND '2020-12-31' LIMIT 21; args=('2020-01-01', '2020-12-31')
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE EXTRACT(MONTH FROM `book`.`pub_date`) = 12 LIMIT 21; args=(12,)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE EXTRACT(DAY FROM `book`.`pub_date`) = 11 LIMIT 21; args=(11,)
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`pub_date` IS NULL LIMIT 21; args=()
(0.000) SELECT VERSION(); args=None
(0.000) SELECT `book`.`id`, `book`.`title`, `book`.`state`, `book`.`pub_date`, `book`.`price`, `book`.`publish` FROM `book` WHERE `book`.`title` REGEXP BINARY '^j' LIMIT 21; args=('^j',)
[06/Jul/2021 10:30:29] "GET /book/ HTTP/1.1" 200 2