08Mysql与python交互

文章目录

mysql驱动模块connector的语法
SQL注入攻击案例
SQL预编译机制防御SQL注入攻击
MySQLconnect异常处理
数据库连接池
mysql connect删除数据
实战：mysqlconnector模块综合使用

mysql驱动模块connector的语法

# -*- encoding: utf-8 -*-
"""
@File    : demo_1.py
@Time    : 2021-08-06 14:37
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
import mysql.connector
con = mysql.connector.connect(host="localhost", port=3306,user="root", password="xd19970306",database="demo"
)con.close()#另外一种连接
import mysql.connector
config = {"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo"
}
con = mysql.connector.connect(**config)
print("finish!")#游标
cursor = con.cursor()
sql = "SELECT empno, ename, hiredate FROM t_emp;"
cursor.execute(sql)
for one in cursor:print(one[0], one[1], one[2])

finish!
7369 SMITH 1980-12-17
7499 ALLEN 1981-02-20
7521 WARD 1981-02-22
7566 JONES 1981-04-02
7654 MARTIN 1981-09-28
7698 BLAKE 1981-05-01
7782 CLARK 1981-06-09
7788 SCOTT 1982-12-09
7839 KING 1981-11-17
7844 TURNER 1981-09-08
7876 ADAMS 1983-01-12
7900 JAMES 1981-12-03
7902 FORD 1981-12-03
7934 MILLER 1982-01-23Process finished with exit code 0

SQL注入攻击案例

cursor.execute(sql%(username,password))

cursor.execute(sql,(username,password))

import mysql.connector
config={"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"vega"
}
con=mysql.connector.connect(**config)
username="1 OR 1=1"
password="1 OR 1=1"
sql="SELECT COUNT(*) FROM t_user WHERE username=%s " \"AND AES_DECRYPT(UNHEX(password),'HelloWorld')=%s"
cursor=con.cursor()
cursor.execute(sql%(username,password))
print(cursor.fetchone()[0])
con.close()

SQL预编译机制防御SQL注入攻击

预编译也可以提升查询速度

import mysql.connector
config={"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"vega"
}
con=mysql.connector.connect(**config)
username="1 OR 1=1"
password="1 OR 1=1"
sql="SELECT COUNT(*) FROM t_user WHERE username=%s " \"AND AES_DECRYPT(UNHEX(password),'HelloWorld')=%s"
cursor=con.cursor()
cursor.execute(sql,(username,password))
print(cursor.fetchone()[0])
con.close()

MySQLconnect异常处理

# -*- encoding: utf-8 -*-
"""
@File    : demo_3.py
@Time    : 2021-08-09 10:20
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
import mysql.connector
try:con=mysql.connector.connect(host="localhost",port=3306,user="root",password="xd19970306",database="demo")con.start_transaction()cursor=con.cursor()sql="INSERT INTO t_emp(empno,ename,job,mgr,hiredate,sal,comm,deptno) " \"VALUES(%s,%s,%s,%s,%s,%s,%s,%s)"cursor.execute(sql,(9680,"赵娜","SALESMAN",None,"1985-12-1",2500,None,10))con.commit()
except Exception as e:if "con" in dir():con.rollback()print(e)
finally:if "con" in dir():con.close()

数据库连接池

#数据库连接是一种关键的 有限的 昂贵的 资源，在并发执行的应用程序中体现的尤为重要
#应用程序<-TCP协议->数据库
#用数据库连接池解决这个问题
#预先创建出一些数据库连接，然后缓存起来，避免了重复创建销毁
import mysql.connector.pooling
config={"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo"
}
try:pool=mysql.connector.pooling.MySQLConnectionPool(**config,pool_size=10)con=pool.get_connection()#开启事务con.start_transaction()cursor=con.cursor()sql="UPDATE t_emp SET sal=sal+%s WHERE deptno=%s"cursor.execute(sql,(200, 20))con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

mysql connect删除数据

# -*- encoding: utf-8 -*-
"""
@File    : demo_4.py
@Time    : 2021-08-09 13:55
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
#数据库连接是一种关键的 有限的 昂贵的 资源，在并发执行的应用程序中体现的尤为重要
#应用程序<-TCP协议->数据库
#用数据库连接池解决这个问题
#预先创建出一些数据库连接，然后缓存起来，避免了重复创建销毁
import mysql.connector.pooling
config={"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo"
}
try:pool=mysql.connector.pooling.MySQLConnectionPool(**config,pool_size=10)con=pool.get_connection()#开启事务con.start_transaction()cursor=con.cursor()#sql="DELETE e, d FROM t_emp e JOIN t_dept d ON e.deptno=d.deptno WHERE d.detpno = 20"sql="DELETE e,d FROM t_emp e JOIN t_dept d ON e.deptno=d.deptno WHERE d.deptno=20"cursor.execute(sql)con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

使用truncat

# -*- encoding: utf-8 -*-
"""
@File    : demo_4.py
@Time    : 2021-08-09 13:55
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
#数据库连接是一种关键的 有限的 昂贵的 资源，在并发执行的应用程序中体现的尤为重要
#应用程序<-TCP协议->数据库
#用数据库连接池解决这个问题
#预先创建出一些数据库连接，然后缓存起来，避免了重复创建销毁
import mysql.connector.pooling
config={"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo"
}
try:pool=mysql.connector.pooling.MySQLConnectionPool(**config,pool_size=10)con=pool.get_connection()#开启事务#con.start_transaction()cursor=con.cursor()#sql="DELETE e, d FROM t_emp e JOIN t_dept d ON e.deptno=d.deptno WHERE d.detpno = 20"#truncate 不依赖于事务机制   sql = "TRUNCATE TABLE t_emp"cursor.execute(sql)#con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

反复执行

#反复执行 excutemany()
import mysql.connector.pooling
config = {"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo",
}
try:pool = mysql.connector.pooling.MySQLConnectionPool(**config,pool_size = 10)con = pool.get_connection()con.start_transaction()cursor = con.cursor()sql = "INSERT INTO t_dept(deptno, dname, loc) VALUES(%s, %s, %s)"data = [[100,"A部门","北京"],[110,"B部门","上海"]]cursor.executemany(sql,(data))con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

实战：mysqlconnector模块综合使用

# -*- encoding: utf-8 -*-
"""
@File    : demo_7.py
@Time    : 2021-08-09 22:28
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
import mysql.connector.pooling
config = {"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo",
}
try:pool = mysql.connector.pooling.MySQLConnectionPool(**config,pool_size = 10)con = pool.get_connection()con.start_transaction()#ddl语句 不受事务机制影响cursor = con.cursor()#创建新表并且复制数据#sql = "CREATE TABLE t_emp_new AS (SELECT * FROM t_emp)"#单纯创建表结构sql = "DROP TABLE t_emp_new"cursor.execute(sql)sql = "CREATE TABLE t_emp_new LIKE t_emp"cursor.execute(sql)sql = "SELECT AVG(sal) AS avg FROM t_emp"cursor.execute(sql)temp = cursor.fetchone()avg = temp[0]sql = "SELECT deptno FROM t_emp GROUP BY deptno HAVING AVG(sal)>=%s"cursor.execute(sql, [avg])#print(cursor.fetchone()[0])#print(cursor.fetchall())# for one in cursor:#     print(one[0])temp = cursor.fetchall()sql = "INSERT INTO t_emp_new SELECT * FROM t_emp WHERE deptno IN ("for index in range(len(temp) - 1):one = temp[index][0]sql += str(one) + ","sql += str(temp[-1][0])sql += ")"print(sql)cursor.execute(sql)sql = "DELETE FROM t_emp WHERE deptno IN ("for index in range(len(temp) - 1):one = temp[index][0]sql += str(one) + ","sql += str(temp[-1][0])sql += ")"cursor.execute(sql)sql = "SELECT deptno FROM t_dept WHERE dname=%s"cursor.execute(sql, ['SALES'])deptno = cursor.fetchone()[0]sql = "UPDATE t_emp_new SET deptno=%s"cursor.execute(sql,[deptno])con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

# -*- encoding: utf-8 -*-
"""
@File    : demo_8.py
@Time    : 2021-08-10 2:17
@Author  : XD
@Email   : gudianpai@qq.com
@Software: PyCharm
"""
import mysql.connector.pooling
config = {"host":"localhost","port":3306,"user":"root","password":"xd19970306","database":"demo",
}
try:pool = mysql.connector.pooling.MySQLConnectionPool(**config,pool_size=10)con = pool.get_connection()con.start_transaction()sql = "INSERT INTO t_dept (SELECT MAX(deptno)+10,%s,%s FROM t_dept UNION SELECT MAX(deptno)+20,%s,%s FROM t_dept)"cursor=con.cursor()cursor.execute(sql,("C部门","西安","D部门","广州"))con.commit()
except Exception as e:if "con" in dir():#回滚（就是返回初始状态）con.rollback()print(e)

10   ACCOUNTING  NEW YORK
20  RESEARCH    DALLAS
30  SALES   CHICAGO
40  OPERATIONS  BOSTON
50  A部门 北京
60  B部门 上海

note

#不能既在一个数据表中查询数据，又写入数据。
#You can't specify target table 't_dept' for update in FROM clause
#多条查询语句会遇到上述情况
INSERT INTO t_dept(deptno, dname, loc)
VALUES((SELECT MAX(deptno) FROM t_dept)
+ 10,
"A部门","北京")

#调整
INSERT INTO t_dept
(SELECT MAX(deptno)+10,"A部门",
"北京" FROM t_dept UNION
SELECT MAX(deptno)+20,"B部门",
"上海" FROM t_dept
)

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08Mysql与python交互

文章目录

mysql驱动模块connector的语法

SQL注入攻击案例

SQL预编译机制防御SQL注入攻击

MySQLconnect异常处理

数据库连接池

mysql connect删除数据

实战：mysqlconnector模块综合使用

08Mysql与python交互相关推荐

最新文章

热门文章

08Mysql与python交互

文章目录

mysql驱动模块connector的语法

SQL注入攻击案例

SQL预编译机制 防御SQL注入攻击

MySQLconnect异常处理

数据库连接池

mysql connect删除数据

实战：mysqlconnector模块综合使用

08Mysql与python交互相关推荐

最新文章

热门文章

SQL预编译机制防御SQL注入攻击