Flask-SQLAlchemy 的 query 是直接查询 model,查出来的一定是一个 model 对象。 类似于: SELECT*FROMexample_table; 如果要查询单个字段的话,应该用 session 去 query model: a=db.session.query(ExampleTable.id,ExampleTable.name).all() 或者 a=ExampleTable.query.with_entities(example_table.id,example_tab...
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...
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...
INSERT INTO tab (id) select (a.id+b.id+c.id)*abs(random()%1e7) from tab a, tab b, tab c limit 5e5; INSERT INTO tab (id) select (a.id+b.id+c.id)*abs(random()%1e7) from tab a, tab b, tab c limit 5e5; INSERT INTO tab (id) select (a.id+b.id+c.id)*abs(rand...
In the example below, we will select all columns where the student's major is English. query = Student.select().where(Student.columns.Major == 'English') output = conn.execute(query) print(output.fetchall()) Powered By Output: [(1, 'Matthew', 'English', True), (4, 'Ben', '...
Example #4 Code: fromSQLAlchemyimporttextres=engine.execute(text("SELECT id, name \ FROM test3 LIMIT 3;"))print(f"We selected {res.rowcount} rows.")forainres.fetchall():print(a) Output: We used SQLAlchemy in different areas in the above examples and passed the SQLAlchemy package with...
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 ...
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 ...
from sqlalchemy import create_engine engine = create_engine('sqlite:///example.db') 3.执行SQL语句: 使用execute()方法来执行SQL语句。例如: from sqlalchemy.sql import text with engine.connect() as connection: result = connection.execute(text("SELECT * FROM users WHERE id=:id"), id=1) for...
珠意，在SQLAlchemy 2.0中，`Query.select_from()`函数已经被取消，而是使用`Query.select()`函数来...