用pymysql操作数据库

import pymysql

# 打开数据库连接
connection = pymysql.connect(host='127.0.0.1',
                             user='root',
                             passwd='146',
                             db='student',  # 数据库名
                             port=3306,
                             charset='utf8'
                             )
try:
    # 使用cursor()方法获取操作游标
    # cur = connection.cursor()  # 获取到的结果是元组
    cur = connection.cursor(pymysql.cursors.DictCursor)  # 获取到的结果是字典
    # SQL 插入语句
    sql = "select id,course from course"  # 执行sql语句
    connection.commit()  # 当有数据被修改时提交到数据库执行

    ret = cur.execute(sql)
    print(ret)
    con = cur.fetchone()
    print(con)
    con = cur.fetchmany(3)
    # con = cur.fetchall()
    print(con)
    cur.close()
except Exception:
    connection.rollback()  # 如果发生错误则回滚
finally:
    # 关闭数据库连接
    connection.close()