核心概念

• Engine：数据库连接的引擎，负责与数据库通信

• Session：数据库会话，管理所有持久化操作

• Model：数据模型类，对应数据库中的表

• Query：查询对象，用于构建和执行数据库查询

连接数据库

python

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

# 创建数据库连接引擎
# SQLite示例
engine = create_engine('sqlite:///example.db', echo=True)

# PostgreSQL示例
# engine = create_engine('postgresql://username:password@localhost:5432/mydatabase')

# MySQL示例
# engine = create_engine('mysql+mysqlconnector://username:password@localhost:3306/mydatabase')

# 创建会话工厂
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 创建会话实例
session = SessionLocal()

创建数据库表

python

# 创建所有表
Base.metadata.create_all(bind=engine)

# 删除所有表
# Base.metadata.drop_all(bind=engine)

创建数据

python

# 创建新用户
new_user = User(name="张三", email="zhangsan@example.com")
session.add(new_user)
session.commit()

# 批量创建
session.add_all([
    User(name="李四", email="lisi@example.com"),
    User(name="王五", email="wangwu@example.com")
])
session.commit()

读取数据

python

# 获取所有用户
users = session.query(User).all()

# 获取第一个用户
first_user = session.query(User).first()

# 根据ID获取用户
user = session.query(User).get(1)

更新数据:

t.bilibili.com/1115545294765817857/
t.bilibili.com/1115545260395593733/
t.bilibili.com/1115545226035855364/
t.bilibili.com/1115545187384295425/
t.bilibili.com/1115545153040285698/
t.bilibili.com/1115545114397114372/
t.bilibili.com/1115545080001724420/
t.bilibili.com/1115545041393156099/
t.bilibili.com/1115545007040757762/
t.bilibili.com/1115544968376614919/
t.bilibili.com/1115544933981224966/
t.bilibili.com/1115544895360073728/
t.bilibili.com/1115544861008723975/
t.bilibili.com/1115544822315221001/
t.bilibili.com/1115544788002668551/
t.bilibili.com/1115544749344817158/
t.bilibili.com/1115544714941038595/
t.bilibili.com/1115544676309401608/
t.bilibili.com/1115544641973780485/
t.bilibili.com/1115544603306491905/
t.bilibili.com/1115544568936267793/
t.bilibili.com/1115544530270027777/
t.bilibili.com/1115544495928115206/
t.bilibili.com/1115544461546356737/
t.bilibili.com/1115544422923108354/
t.bilibili.com/1115544388531912704/
t.bilibili.com/1115544349907615750/
t.bilibili.com/1115544315504885769/
t.bilibili.com/1115544276864860162/
t.bilibili.com/1115544242536579081/
t.bilibili.com/1115544203869290499/
t.bilibili.com/1115544165189419012/
t.bilibili.com/1115544130843312132/
t.bilibili.com/1115544092204335106/
t.bilibili.com/1115544057825722371/
t.bilibili.com/1115544019160530946/
t.bilibili.com/1115543984785063937/
t.bilibili.com/1115543946185932804/
t.bilibili.com/1115543911816757265/
t.bilibili.com/1115543873131642880/
t.bilibili.com/1115543838807556104/
t.bilibili.com/1115543800099373059/
t.bilibili.com/1115543765780529155/
t.bilibili.com/1115543727102754824/
t.bilibili.com/1115543692763987975/
t.bilibili.com/1115543649797537795/
t.bilibili.com/1115543615437799433/
t.bilibili.com/1115543576807211014/
t.bilibili.com/1115543542441181209/
t.bilibili.com/1115543508051034114/
t.bilibili.com/1115543469413105673/
t.bilibili.com/1115543430737428484/
t.bilibili.com/1115543396416487428/
t.bilibili.com/1115543357735567381/
t.bilibili.com/1115543323409383426/
t.bilibili.com/1115543284756774915/
t.bilibili.com/1115543250361384960/
t.bilibili.com/1115543211685707784/
t.bilibili.com/1115543177373155348/
t.bilibili.com/1115543142990348289/
t.bilibili.com/1115543104311525381/
t.bilibili.com/1115543065659965440/
t.bilibili.com/1115543031339024384/
t.bilibili.com/1115542996962508808/
t.bilibili.com/1115542958285783062/
t.bilibili.com/1115542923986862087/
t.bilibili.com/1115542885309087745/
t.bilibili.com/1115542850952495105/
t.bilibili.com/1115542812285206537/
t.bilibili.com/1115542777957974024/
t.bilibili.com/1115542739239305218/
t.bilibili.com/1115542704930947077/
t.bilibili.com/1115542666259464196/
t.bilibili.com/1115542631926988806/
t.bilibili.com/1115542593264943110/
t.bilibili.com/1115542558907301891/
t.bilibili.com/1115542520242110470/
t.bilibili.com/1115542485865594886/
t.bilibili.com/1115542447184674816/
t.bilibili.com/1115542412885753857/
t.bilibili.com/1115542374196445204/
t.bilibili.com/1115542339854532609/
t.bilibili.com/1115542301204021257/
t.bilibili.com/1115542266836942855/
t.bilibili.com/1115542228202160162/
t.bilibili.com/1115542193818304513/
t.bilibili.com/1115542155180376067/
t.bilibili.com/1115542120827977730/
t.bilibili.com/1115542082163834884/
t.bilibili.com/1115542047795707908/
t.bilibili.com/1115542009136807942/
t.bilibili.com/1115541974795943937/
t.bilibili.com/1115541936090906633/
t.bilibili.com/1115541901780451333/
t.bilibili.com/1115541863084851204/
t.bilibili.com/1115541824469991428/
t.bilibili.com/1115541747144851462/
t.bilibili.com/1115541708509020161/
t.bilibili.com/1115541674116775943/
t.bilibili.com/1115541635446341638/
t.bilibili.com/1115541601135886354/
t.bilibili.com/1115541562423508993/
t.bilibili.com/1115541528114102275/
t.bilibili.com/1115541489431085064/
t.bilibili.com/1115541455075540995/
t.bilibili.com/1115541416394620933/
t.bilibili.com/1115541382058999811/
t.bilibili.com/1115541343387516933/
t.bilibili.com/1115541309027778562/
t.bilibili.com/1115541270422355984/
t.bilibili.com/1115541236025917448/
t.bilibili.com/1115541201690296328/
t.bilibili.com/1115541163047124999/
t.bilibili.com/1115541128626569219/
t.bilibili.com/1115541089997029377/
t.bilibili.com/1115541055675039746/
t.bilibili.com/1115541017006702599/
t.bilibili.com/1115540982627041283/
t.bilibili.com/1115540943977578503/
t.bilibili.com/1115540909639860231/
t.bilibili.com/1115540870992494595/
t.bilibili.com/1115540836582424579/
t.bilibili.com/1115540797957079063/
t.bilibili.com/1115540763604680705/
t.bilibili.com/1115540724940537864/
t.bilibili.com/1115540690599673861/
t.bilibili.com/1115540651946016769/
t.bilibili.com/1115540617584181254/
t.bilibili.com/1115540578927378436/
t.bilibili.com/1115540544531988485/
t.bilibili.com/1115540505917128708/
t.bilibili.com/1115540471559487489/
t.bilibili.com/1115540432876470281/
t.bilibili.com/1115540398487371783/
t.bilibili.com/1115540359844200453/
t.bilibili.com/1115540325518016519/
t.bilibili.com/1115540286863310852/
t.bilibili.com/1115540252508815364/
t.bilibili.com/1115540213825798164/
t.bilibili.com/1115540179497517064/
t.bilibili.com/1115540140843859991/
t.bilibili.com/1115540106434838535/
t.bilibili.com/1115540067816833033/
t.bilibili.com/1115540033437171719/
t.bilibili.com/1115539994782466048/
t.bilibili.com/1115539956140343298/
t.bilibili.com/1115539917477249030/
t.bilibili.com/1115539883113316357/
t.bilibili.com/1115539844460707846/
t.bilibili.com/1115539810106212353/
t.bilibili.com/1115539771433680903/
t.bilibili.com/1115539737120079875/
t.bilibili.com/1115539698451742724/
t.bilibili.com/1115539664047964164/
t.bilibili.com/1115539625442541572/
t.bilibili.com/1115539591045054467/
t.bilibili.com/1115539552419708931/
t.bilibili.com/1115539518073602053/
t.bilibili.com/1115539479386390531/
t.bilibili.com/1115539445041332227/