python中mysql基础 *** 作

import pymysql

# 连接数据库
db = pymysql.connect(
    host='localhost',
    user='test',
    password="liang4",
    port=3306,
    database='test',
    autocommit=False
)

# 创建游标
cursor = db.cursor()

# # 创建表格student-(name, sex, age, score)
# cursor.execute('drop table if EXISTS student')  # 如果存在则删除student
# sql = '''
#     create table `student` (
#     num int(8) primary key auto_increment,
#     name varchar(30) not null,
#     sex varchar(5),
#     age int(2),
#     score float(3,1)
#     )
#     '''
# cursor.execute(sql)

# # 插入单条数据
# sql = '''
#     insert into student (name, sex, age, score) values ('liang', 'girl', 25, 60)
#     '''
# cursor.execute(sql)
# db.commit()  # 提交事务，必须加这个

# # 插入多条数据
# sql = '''
#      insert into student (name, sex, age, score) values (%s, %s, %s, %s)
#      '''
# add_data_list = [
#     ('wang', 'boy', 24, 59),
#     ('yuan', 'girl', 26, 100)   # 100输出99.9，因为前面设置的score float(3,1)
# ]
# cursor.executemany(sql, add_data_list)
# db.commit()

# # 数据表更新
# sql = '''
#     update student set score=%s where num=%s
# '''
# cursor.execute(sql, (90, 1))
# db.commit()

# # 数据表删除
# sql = '''
#     delete from student where num=2
# '''
# try:
#     cursor.execute(sql)
#     db.commit()
#     print('succeed!')
# except:
#     # 如果出现异常，回滚（要求autocommit=False，autocommit在pymysql.connect中设置）
#     db.rollback()
#     print('failed!')
# finally:
#     cursor.close()
#     db.close()

# # 查询数据表
# sql = '''
#     select * from student where age=25
# '''
# try:
#     cursor.execute(sql)
#     result = cursor.fetchall()  # 把所有行都取出来
#     print(type(result))
#     print(result)
#     for row in result:
#         num = row[0]
#         name = row[1]
#         sex = row[2]
#         age = row[3]
#         score = row[4]
#         print('num:', num, 'name:', name, 'sex:', sex, 'age:', age, 'score:', score)
# except Exception as e:
#     print(e)
#     print('failed')
# finally:
#     cursor.close()
#     db.close()


# 关闭游标,关闭数据库连接
cursor.close()
db.close()

感谢这位博主提供很多有效的帮助
https://blog.csdn.net/u011027547/article/details/122520529