Python编程：使用sqlalchemy对数据库进行增删改查

文档：​​https://docs.sqlalchemy.org/en/13/core/engines.html​​

链接字符串

# default
engine = create_engine('mysql://scott:tiger@localhost/foo')

# mysqlclient (a maintained fork of MySQL-Python)
engine = create_engine('mysql+mysqldb://scott:tiger@localhost/foo')

# PyMySQL
engine = create_engine('mysql+pymysql://scott:tiger@localhost/foo')

管理数据库连接

# -*- coding: utf-8 -*-

from sqlalchemy import create_engine, text

db_url = "mysql://root:123456@127.0.0.1:3306/demo"

engine = create_engine(db_url, echo=True)

db = engine.connect()

db.close()

备注：echo 参数可以开启SQL语句日志打印

1、插入数据

insert = "insert into student(name)values(:name)"

# 插入数据 单条
dct = {"name": "Tom"}

result = db.execute(text(insert), dct)
print(result.rowcount)  # 1

# 插入数据 多条
# 注意:
# peewee的特殊字符: %
# pymysql的特殊字符: ?
# 都能正常写入，不需要特殊转义

data = [
    {"name": "Tom"},
    {"name": "Tom?"},
    {"name": "Tom%"}
]

result = db.execute(text(insert), data)
print(result.rowcount) # 3

2、删除数据

delete = "delete from student where id=1"
result = db.execute(text(delete))
print(result.rowcount) # 1

3、修改数据

update = "update student set sex='2' where id=1"
result = db.execute(text(update))
print(result.rowcount)  # 1

4、查询数据

select = "select id, name from student where id=1"
result = db.execute(text(select))
print(result.keys())  # ['id', 'name']
print(result.fetchall())  # [(50, 'Tom')]
print(result.rowcount)  # 1

for row in cursor:
   print(row["name"])