要选择某个字段,您可以使用SQLAlchemy中的select函数。例如,假设您有一个名为users的表格,其中包含id,name和age字段。要选择name字段,您可以执行以下操作: from sqlalchemy import create_engine, Table, Column, Integer, String, MetaData # 创建一个连接到数据库的引擎 engine = create_engine('sqlite:///examp...
查询数据。使用 SQLAlchemy 的 select() 函数执行查询，以获取表中的数据。示例代码：from sqlalchemy import select with engine.connect() as conn:result = conn.execute(select([users])).fetchall()for row in result:print(row)更新数据。使用 SQLAlchemy 的 update() 函数更新表中的数据。示...
from SQLAlchemy import text res = engine.execute( text( "SELECT id, name \ FROM test3;" ) ) print(res) Output: Example #4 Code: from SQLAlchemy import text res = engine.execute( text( "SELECT id, name \ FROM test3 LIMIT 3;" ) ) print(f"We selected {res.rowcount} rows.") f...
from sqlalchemy.future import select from sqlalchemy.orm import aliased from sqlalchemy.ext.asyncio import AsyncSession from sqlalchemy.ext.asyncio import create_async_engine from sqlalchemy.orm import sessionmaker # 假设你的数据库模型是 DictDataInfo 和 DictTypeInfo # 需要提前定义好这两个模型类 DA...
result=await session.execute("SELECT * FROM dict_type_info WHERE pid IS NULL") parent_nodes=result.scalars().all()fornodeinparent_nodes:print(f"Parent Node: {node.name},Children: {[child.name for child in node.children]}") 代码说明 ...
from sqlalchemy import create_engine, Column, Integer, String, select from sqlalchemy.orm import sessionmaker from sqlalchemy.ext.declarative import declarative_base # 创建数据库引擎 engine = create_engine('sqlite:///example.db', echo=True) # 定义 Base 类 Base = declarative_base() # 定义 Us...
all() return total, result # 调用 conditions = { "status": 1, } queryByPage(1, 5, conditions) # 生成SQL """ SELECT * FROM ym_user WHERE ym_user.status = 1 ORDER BY ym_user.id DESC LIMIT 0, 5 """ 6.4 使用文本SQL def queryByTextSQL(): """ 使用文本SQL查询 """ with ...
session = Session() # Users is the table from the earlier example result = await session.execute( Users.select.with_only_columns(Users.c.name) ) print(result.fetchall()) await session.close() await engine.dispose() asyncio.run(async_main())...
((SELECT coalesce(max(foo.foopk) + %(max_1)s, %(coalesce_2)s) AS coalesce_1 FROM foo), %(bar)s) RETURNING foo.foopk 新版本 1.3 中:现在可以在 ORM 刷新期间将 SQL 表达式传递给主键列;如果数据库支持 RETURNING,或者正在使用 pysqlite,ORM 将能够将服务器生成的值作为主键属性的值检索出来。
从SQLAlchemy 1.4开始Query构造与Select构造,使这两个对象基本相同。 Listing of files: filter_public.py- Illustrates a global criteria applied to entities of a particular type. temporal_range.py- Illustrates a custom per-query criteria that will be applied to selected entities. ...