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325 lines
12 KiB
325 lines
12 KiB
from sqlalchemy import create_engine, text, insert, update, select, delete, engine_from_config, or_, and_, func |
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from sqlalchemy.orm import Session, sessionmaker |
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import configparser |
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import sys |
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sys.path.append(r'..') |
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from sqlalchemy_14.db_schema import User, Student |
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# 创建引擎 |
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HOST = "home.rogersun.cn" |
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USER = "root" |
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PWD = "Sxzgx1209" |
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PORT = "3306" |
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DB = "orm_sqlalchemy" |
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URI = f"mysql+pymysql://{USER}:{PWD}@{HOST}:{PORT}/{DB}?charset=utf8mb4" |
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engine = create_engine( |
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URI, |
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echo=True, # echo = 'debug' |
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future=True, # 使用2.0接口 |
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pool_size=5, # 连接池设置，0表示无限制 |
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max_overflow=0, # 设置溢出 |
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pool_timeout=30, # |
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pool_recycle=3600, # 设置时间以限制多久自动断开 |
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pool_logging_name='test_pool', # |
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pool_pre_ping=True, |
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isolation_level="AUTOCOMMIT", |
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query_cache_size=200, |
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) |
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# 从配置文件获取数据库链接 |
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# config = configparser.ConfigParser() |
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# config.read_file(open('config.ini', 'r')) |
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# print(config.items('db_source')) |
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# engine = engine_from_config(dict(config.items('db_source')), pool_size=1, max_overflow=0, pool_timeout=0.1) |
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# 执行纯sql |
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# 无参数 |
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# stmt = text("SELECT * FROM user") |
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# with engine.connect() as conn: |
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# result = conn.execute(stmt).all() |
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# print(result) |
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# 有参数 |
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# with engine.connect() as conn: |
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# stmt = text("INSERT INTO user (name, password) VALUES (:name, :password)") |
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# params = [{'name': 'test1', 'password': 'test1pwd'}, {'name': 'test2', 'password': 'test2pwd'}] |
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# result = conn.execute(stmt, params) |
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# print(result) |
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# conn.commit() |
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# 绑定参数 todo 不成功 |
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# with engine.connect() as conn: |
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# stmt = text("INSERT INTO user (name, password) VALUES (:name, :password)").bindparams( |
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# {'name': 'test3', 'password': 'test3pwd'}) |
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# result = conn.execute(stmt) |
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# print(result) |
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# conn.commit() |
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# 获取结果 |
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# stmt = text("SELECT * FROM user") |
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# with engine.connect() as conn: |
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# result = conn.execute(stmt) |
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# 解包赋值 |
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# for _id, name, password in result: |
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# print(f"name: {name}, password: {password}") |
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# 列指定的名称 |
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# for row in result: |
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# name, password = row.name, row.password |
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# print(f"name: {name}, password: {password}") |
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# 绑定模型 |
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# result: [User] = result.fetchall() |
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# for row in result: |
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# name = row.name |
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# password = row.password |
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# print(f"name: {name}, password: {password}") |
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# 创建Session实例 |
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# with Session(engine) as session: |
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# stmt = text("SELECT * FROM user") |
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# result = session.execute(stmt) |
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# for row in result: |
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# print(f"name: {row.name} - password: {row.password}") |
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# 2.0 增删改查 |
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db_session = sessionmaker(bind=engine)() |
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# insert 方式1 |
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# insert_stmt = insert(User).values({'name': 'sql2_test1', 'password': 'pwd1'}) |
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# with db_session as sess: |
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# result = sess.execute(insert_stmt) |
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# print(result) |
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# sess.commit() |
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# insert 方式2 |
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insert_stmt2 = insert(User) |
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insert_data2 = {'name': 'sql2_test2', 'password': 'pwd2'} |
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# with db_session as sess: |
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# result = sess.execute(insert_stmt2, insert_data2) |
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# print(result) |
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# sess.commit() |
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# insert 批量插入 |
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# insert_data3 = [{'name': 'sql2_test3', 'password': 'pwd3'}, {'name': 'sql2_test4', 'password': 'pwd4'}] |
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# with db_session as sess: |
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# result = sess.execute(insert_stmt2, insert_data3) |
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# sess.commit() |
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# insert begin方式 |
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# insert_data4 = [{'name': 'sql2_test5', 'password': 'pwd5'}, {'name': 'sql2_test6', 'password': 'pwd6'}] |
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# with db_session.begin(): |
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# db_session.execute(insert_stmt2, insert_data4) |
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# db_session.commit() |
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# |
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# insert 对像方式 |
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# insert_obj1 = User(name='sql2_test7', password='pwd7') |
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# with db_session as sess: |
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# sess.add(insert_obj1) |
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# sess.commit() |
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# insert 对象方式 批量 |
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# insert_obj2 = User(name='sql2_test8', password='pwd8') |
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# with db_session as sess: |
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# # sess.bulk_save_objects([insert_obj2, insert_obj3]) |
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# sess.add_all([insert_obj2, insert_obj3]) |
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# sess.commit() |
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# add |
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# with db_session as sess: |
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# user_obj = User(name='add', password='addpwd123') |
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# sess.add(user_obj) |
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# sess.flush() # 刷新数据库表 |
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# print(user_obj.id) # 获取数据对应id |
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# sess.commit() |
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# 查 |
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# get 通过id |
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# result = db_session.get(User, 4) |
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# print(result) |
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# sqlalchemy1.4: session.query(User).all() |
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# query_cursor = db_session.execute(select(User)) |
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# print(query_cursor.all()) # 数据指针，当all取过数据后one将得到None |
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# print(query_cursor.first()) |
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# for row in query_cursor.scalars(): |
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# print(row) # row.name格式可以取到数据 |
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# sqlalchemy1.4: session.query(User).filter_by(name='roger').all() |
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# sql_stmt = select(User).filter_by(name='roger') |
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# query_result = db_session.execute(sql_stmt).one() |
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# print(query_result) |
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# print(query_result[0].name) |
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# sqlalchemy1.4: session.query(User).filter(User.id == 2).all() |
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# sql_stmt = select(User).where(User.id == 2) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id >= 2).first() |
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# sql_stmt = select(User).where(User.id >= 2) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id >= 2).order_by(User.id.desc()).all() |
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# sql_stmt = select(User).where(User.id >= 2).order_by(User.id.desc()) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id >= 2).filter(User.name.like('%one%')).all() |
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# sql_stmt = select(User).where(User.id >= 2).where(User.name.like('%one%')) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id.in_([1, 2, 3])).all() |
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# sql_stmt = select(User).where(User.id.in_([1, 2, 3])) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id.in_(session.query(User.id).filter(User.name.startswith('he')))).all() |
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# 连写 |
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# sql_stmt = select(User).where(User.id.in_( |
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# db_session.execute(select(User.id).where(User.name.startswith('he'))).scalars())) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# 拆分 |
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# sql_stmt1 = select(User.id).where(User.name.startswith('he')) |
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# query_result1 = db_session.execute(sql_stmt1).scalars() |
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# sql_stmt2 = select(User).where(User.id.in_(query_result1)) |
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# query_result2 = db_session.execute(sql_stmt2).scalars() |
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# for row in query_result2: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.id.notin_([1, 2])).all() |
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# sql_stmt = select(User).where(User.id.notin_([1, 2])) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.password is None).all() |
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# sqlalchemy1.4: session.query(User).filter(User.password.is_(None)).all() |
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# sql_stmt = select(User).where(User.password.is_(None)) # 此处不支持 is None |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(User.password is not None).all() |
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# sqlalchemy1.4: session.query(User).filter(User.password.isnot(None)).all() |
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# sql_stmt = select(User).where(User.password.isnot(None)) # isnot() |
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# sql_stmt = select(User).where(User.password.is_not(None)) # is_not() |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(or_(User.id > 2, User.name.ilike('Rog%'))).all() |
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# sql_stmt = select(User).where(or_(User.id > 2, User.name.ilike('ROG%'))) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User).filter(and_(User.id >= 2, User.name.endswith('ei'))) |
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# sql_stmt = select(User).where(and_(User.id >= 2, User.name.endswith('ei'))) |
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# query_result = db_session.execute(sql_stmt).scalars() |
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# for row in query_result: |
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# print(f"{row.id} - {row.name} - {row.password}") |
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# sqlalchemy1.4: session.query(User.name.label('user_name'), User.password).filter(User.id >= 2).all() |
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# sql_stmt = select(User.name.label('user_name_label'), User.password.label('user_pwd_label')).where(User.id >= 2) |
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# query_result = db_session.execute(sql_stmt).all() # 返回 [('honeyhoney', '2222'), ('haha', '123321'), ('hehe', '3333')] |
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# query_result = db_session.execute(sql_stmt).scalars() # 返回 scalars 对象， 仅包含name |
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# query_result = db_session.execute(sql_stmt) # 返回 {'user_name_label': 'roger', 'user_pwd_label': 'rogerpwd123'} 建议此情况 |
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# print(query_result) |
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# for row in query_result: |
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# print(row) |
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# for row in query_result.mappings(): |
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# print(row['user_name_label'], row['user_pwd_label']) |
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# sqlalchemy1.4: session.query(User).filter(User.id > 1).count() |
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# sql_stmt = select(func.count()).select_from(User).where(User.id <= 2) |
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# query_result = db_session.execute(sql_stmt).scalar() |
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# print(query_result) |
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# try: |
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# result = session.query(User).filter(User.id > 1).one() # one 当仅查询到一个结果时返回，否则抛出异常 |
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# except Exception as e: |
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# print(e) |
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# result = session.query(User).filter(User.id == 1).one_or_none() # one_or_none 当查询结果仅一条时显示返回结果，当没有结果时返回None，否则抛出异常 |
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# result = session.query(User).filter(User.id == 1).scalar() # 调用one方法，并在成功时返回行的第一列 |
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# result = session.query(User).filter(User.id > 1).group_by(User.password) |
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# result = session.query(func.max(User.id)).all() # func.max |
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# print(result[0].name, result[0].password) |
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# print(result) # 定义 __repr__ 后可以打印 |
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# select all scalars |
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# result = db_session.execute(select(User)).scalars().all() # [<1 name:rogersun>, <2 name:honeyhoney>, <3 name:haha>] |
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# print(result) |
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# for row in result: |
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# print(f"{row.name} - {row.password}") |
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# select all |
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# result = db_session.execute(select(User)).all() # [(<1 name:rogersun>,), (<2 name:honeyhoney>,), (<3 name:haha>,)] |
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# print(result) |
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# for row in result: |
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# print(f"{row[0].name} - {row[0].password}") |
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# select filter_by |
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# result = db_session.execute(select(User).filter_by(name='roger')).fetchone() |
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# print(result[0].name) |
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# select filter |
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# result = db_session.execute(select(User).where(User.id <= 4)).scalars().all() |
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# print(result) |
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# print(r[0][0].name) |
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# select from_statement |
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# result = db_session.execute(select(User).from_statement(text('SELECT * FROM user'))).scalars().all() |
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# for row in result: |
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# print(row.name) |
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# 遍历数据 |
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# 元组赋值 all |
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# result = db_session.execute(select(User.id, User.name, User.password).where(User.id <= 4)).all() |
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# print(result) |
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# for _id, name, password in result: |
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# print(f"{_id} - {name} - {password}") |
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# # 索引 all |
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# result = db_session.execute(select(User).where(User.id <= 4)).all() |
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# print(result) |
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# for row in result: |
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# _id, name, password = row[0].id, row[0].name, row[0].password |
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# print(f"{_id} - {name} - {password}") |
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# # 属性 scalers |
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# result = db_session.execute(select(User).where(User.id <= 4)).scalars().all() |
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# print(result) |
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# for row in result: |
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# _id, name, password = row.id, row.name, row.password |
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# print(f"{_id} - {name} - {password}") |
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# # 映射 |
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# result = db_session.execute(select(User.id, User.name, User.password).where(User.id <= 4)) |
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# print(result) |
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# for dict_row in result.mappings(): |
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# _id, name, password = dict_row['id'], dict_row['name'], dict_row['password'] |
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# print(f"{_id} - {name} - {password}") |
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# update |
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# r = db_session.execute(update(User).filter_by(name='roger').values(password='rogerpwd123').execution_options( |
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# synchronize_session='evaluate')) |
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# print(r) |
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# db_session.commit() |
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# synchronize_session 有三种选项： false, "fetch", "evaluate"，默认是 evaluate |
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# false 表示完全不更新 Python 中的对象 |
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# fetch 表示重新从数据库中加载一份对象 |
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# evaluate 表示在更新数据库的同时，也尽量在 Python 中的对象上使用同样的操作
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