目录

1， mysql

1-1， mysql驱动

1-2， 连接mysql

1-3， 执行sql语句

1-3-1， 创建表

1-3-2， 插入数据

1-3-3， 查询数据

1-3-4， 获取结果集

1-4， 断开mysql连接

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1， mysql

1-1， mysql驱动

python要连接mysql需要安装mysql驱动

安装mysql的驱动命令：pip install  mysql-connector-python

In [22]: pip install mysql-connector-python
Looking in indexes: http://mirrors.aliyun.com/pypi/simple/
Collecting mysql-connector-pythonDownloading http://mirrors.aliyun.com/pypi/packages/d3/b8/6798a0f91e595c0704a94c1e32a00ca930f77cb8f0f96c7e4dad4f9db1fe/mysql_connector_python-8.1.0-cp311-cp311-win_amd64.whl (10.8 MB)━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 10.8/10.8 MB 777.8 kB/s eta 0:00:00
Requirement already satisfied: protobuf<=4.21.12,>=4.21.1 in c:\users\administrator\appdata\local\programs\python\python311\lib\site-packages (from mysql-connector-python) (4.21.12)
Installing collected packages: mysql-connector-python
Successfully installed mysql-connector-python-8.1.0
Note: you may need to restart the kernel to use updated packages.

1-2， 连接mysql

命令：mysql.connector.conect(user=用户名， password=密码， database=数据库名)

# 导入mysql驱动
In [23]: import mysql.connector# 创建连接
In [24]: conn = mysql.connector.connect(user='xxxx', password='xxxx', database='scott')

1-3， 执行sql语句

要执行sql语句，需要通过"连接"创建游标，在通过游标执行sql语句

cursor = conn.cursor()：创建游标

cursor.excute(sql语句)：执行单挑sql语句

cursor.excutemany(sql语句， 参数列表)

1-3-1， 创建表

# 创建游标
In [27]: cursor = conn.cursor()# 通过sql语句创建表
In [47]: cursor.execute('''create table user(...: id bigint not null,...: name varchar(20) not null,...: job varchar(20) not null,...: constraint pk_user_table primary key (id));''')# 执行sql语句，查询表
In [59]: cursor.execute('show tables;')# 获取查询结果
In [60]: cursor.fetchall()
Out[60]:
[('bbb',),('bbb_1',),('dept',),('emp',),('salgrade',),('snapshot_table',),('user',)]# 执行单条sql语句
# 这里这里的占位符为%s， sql语句与参数之间用的是逗号
In [160]: cursor.execute('insert into user (id, name, job) values (%s, %s, %s);', (20, 'fdsa', 'fdsaf'))# 执行多条sql语句， sql语句与参数之间用的是逗号
In [137]: users
Out[137]: [(4, 'ee', 'ee1'), (5, 'ff', 'ff1')]In [139]: cursor.executemany('''...: insert into user...: (id, name, job)...: values...: (%s, %s, %s);...: ''', users)

1-3-2， 插入数据

# 向数据库中插入数据
In [69]: cursor.execute('''...: insert into user...: (id, name, job)...: values...: (1, 'aa', 'aa1'),...: (2, 'bb', 'bb1'),...: (3, 'cc', 'cc1')...: ''')# 获取收影响的行
In [70]: cursor.rowcount
Out[70]: 3# 更新数据库数据后，需要提交，数据才能保存到数据库中
In [79]: conn.commit()

1-3-3， 查询数据

In [71]: cursor.execute('select * from user;')

1-3-4， 获取结果集

获取结果集通过命令：

cursor.fetchone()：获取结果集一条记录

cursor.fetchmany(n)：根据定义值(n)，获取结果集n条记录

cursor.fetchall()：获取所有结果集

# 通过cursor.fetchall()获取整个结果集
In [72]: cursor.fetchall()
Out[72]: [(1, 'aa', 'aa1'), (2, 'bb', 'bb1'), (3, 'cc', 'cc1')]In [148]: cursor.execute('select * from user;')# 获取结果集中一条记录
In [149]: cursor.fetchone()
Out[149]: (1, 'aa', 'aa1')# 获取结果集中3条记录, 数字3,表示获取3条，根据定义的数字来获取结果集的条数
In [150]: cursor.fetchmany(3)
Out[150]: [(2, 'bb', 'bb1'), (3, 'cc', 'cc1'), (4, 'ee', 'ee1')]# 若结果集没有被获取完时，再次执行sql语句，会报错
# 这时需要通过cursor.fetchall()获取完整结果集后，再执行sql语句
In [151]: cursor.execute('select * from user;')
---------------------------------------------------------------------------
InternalError                             Traceback (most recent call last)
Cell In[151], line 1
----> 1 cursor.execute('select * from user;')File ~\AppData\Local\Programs\Python\Python311\Lib\site-packages\mysql\connector\cursor_cext.py:303, in CMySQLCursor.execute(self, operation, params, multi)301 except (ProgrammingError, ReferenceError) as err:302     raise ProgrammingError("Cursor is not connected", 2055) from err
--> 303 self._cnx.handle_unread_result()305 stmt = ""306 self.reset()File ~\AppData\Local\Programs\Python\Python311\Lib\site-packages\mysql\connector\connection_cext.py:955, in CMySQLConnection.handle_unread_result(self, prepared)953     self.consume_results()954 elif unread_result:
--> 955     raise InternalError("Unread result found")InternalError: Unread result found# 获取完整结果集后，再次执行sql语句成功
In [154]: cursor.fetchall()
Out[154]: [(5, 'ff', 'ff1')]In [156]: cursor.execute('select * from user;')

1-4， 断开mysql连接

操作完mysql后，需要断开连接

cursor.close()：断开游标

conn.close()：断开连接

In [168]: cursor.close()
Out[168]: TrueIn [169]: conn.close()