Python——pymysql 操作数据库

# 引入 pymysql
import pymysql as mysql


def main():
    # 连接数据库
    db = mysql.connect(host='localhost', user='root', password='', db='test', charset='utf8')
    # 创建游标对象
    cursor = db.cursor()
    # sql 语句
    sql = 'SELECT a.*, c.dep_name AS father_dep, b.dep_name FROM person AS a LEFT JOIN department AS b on a.person_department = b.dep_id LEFT JOIN department AS c on b.dep_father_id = c.dep_id'
    try:
        # 执行 sql 语句
        cursor.execute(sql)
        # 将查询语句提交至数据库
        db.commit()
    except:
        # 发生错误时回滚
        db.rollback()
    else:
        # 没发生错误 就输出内容
        print(cursor.fetchall())
    finally:
        # 最后，不管是否发生错误都关闭一下数据库连接
        db.close()


if __name__ == '__main__':
    main()

运行后的内容

((1, '测试一号', 2, '男', '总部', '部门一'), (2, '测试二号', 3, '女', '部门一', '部门二'))