Python SQL生成值列表

import sqlite3

# 连接到SQLite数据库
conn = sqlite3.connect('example.db')
cursor = conn.cursor()

# 手动拼接SQL字符串
sql = "SELECT name FROM users WHERE age > ?"
age_threshold = 25
cursor.execute(sql, (age_threshold,))

# 获取结果并生成值列表
names = [row[0] for row in cursor.fetchall()]
print(names)

# 关闭连接
cursor.close()
conn.close()

import sqlite3

# 连接到SQLite数据库
conn = sqlite3.connect('example.db')
cursor = conn.cursor()

# 使用参数化查询
sql = "SELECT name FROM users WHERE age > ?"
age_threshold = 25
cursor.execute(sql, (age_threshold,))

# 获取结果并生成值列表
names = [row[0] for row in cursor.fetchall()]
print(names)

# 关闭连接
cursor.close()
conn.close()

from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    age = Column(Integer)

# 创建数据库引擎
engine = create_engine('sqlite:///example.db')
Base.metadata.create_all(engine)

# 创建会话
Session = sessionmaker(bind=engine)
session = Session()

# 查询数据并生成值列表
age_threshold = 25
names = [user.name for user in session.query(User).filter(User.age > age_threshold)]
print(names)

# 关闭会话
session.close()

import sqlite3

# 使用上下文管理器自动管理数据库连接
with sqlite3.connect('example.db') as conn:
    cursor = conn.cursor()
    sql = "SELECT name FROM users WHERE age > ?"
    age_threshold = 25
    cursor.execute(sql, (age_threshold,))
    names = [row[0] for row in cursor.fetchall()]
    print(names)