Python operates MySQL database

Python operation MySQL

Install pymysql third-party package

sudo pip install pymysql

There are five processes to operate the database

• 建立和数据库服务器的连接
• 通过连接获取游标
• 使用游标堆数据库进行操作
• 关闭游标资源
• 断开连接

import pymysql

# 1.建立与服务器的连接,获取连接对象
coon = pymysql.connect(host='127.0.0.0', port=3306, user='root', password='mysql', database='school', charset='utf8')

# 2.通过连接获取游标
cur = coon.cursor()

# 3.利用游标操作数据库
sql = "select * from students"
no = cur.execute(sql)
print(no)
# 3.1 获取结果
print(cur.fetchall())

# 3.2发生错误时，回滚
coon.rollback()

# 4.关闭游标
cur.close()

# 5.关闭连接
coon.close()

If you forget what information needs to be filled in to connect to the database, you can view the source code

Various database operations

Get all data at once

cur.fetchall()   #fetch 获取   all  全部

This operation will get all the data of the entire table and display it in the form of tuples,一次只可获取一次

Example result:

((22,xiaoming,man),(23,xiaohong,woman),(24,xiaokeai,man))

Fetch data one row at a time

cur.fetchone()

一次获取一行数据如果写两遍，则获取第一行和第二行数据

CRUD operation

Addition, deletion and modification operations need to modify the sql statement, and then submit it (not submitted by default)

sql = "update student set age = 4 where id = 3"
sql = "insert into student (name,age) VALUES ('小明',12)"
sql = "delete from student where id = 2"
cur.execute(sql)
conn.commit()