Python && MySQL database

Python connected to the database

 

python3 does not support mysqldb (python2 support), instead of using pymysql

But there are claims  https://blog.csdn.net/liuweiyuxiang/article/details/80666773

Here with pymysql

 

Operating procedures

1. Create a connection
2. Gets cursor
3. CRUD operations performed
4. Data processing
5. Close cursor
6. Close connection

 

Create a connection

import pymysql.cursors

HOST = '127.0.0.1'
PORT = 3306
USER = 'root'
PASSWD = 'root'
DB = 'hxx_test'
CHARSET = 'utf8'
#pymysql.cursors.DictCursor

connection = pymysql.connect(host=HOST,
                             port=PORT,
                             user=USER,
                             passwd=PASSWD,
                             db=DB,
                             charset=CHARSET)

Returns cursor objects (the cursor object) used to execute the query and get results

 

Common Parameter Description

 

Gets cursor object

cursor = connection.cursor()

 

Typical Example

import pymysql.cursors

HOST = '127.0.0.1'
PORT = 3306
USER = 'root'
PASSWD = 'root'
DB = 'hxx_test'
CHARSET = 'utf8'
#pymysql.cursors.DictCursor

connection = pymysql.connect(host=HOST,
                             port=PORT,
                             user=USER,
                             passwd=PASSWD,
                             db=DB,
                             charset=CHARSET)

try:
	cursor = connection.cursor()
	sql = "select * from my_first"
	cursor.execute(sql)
	result = cursor.fetchall()
	for data in result:
		print(data)
except Exception:print("查询失败!")

cursor.close()
connection.close()

 

import pymysql.cursors



conn = pymysql.connect(
    host='127.0.0.1',
    port=3306,
    user='root',
    password='root',
    database='hxx_test',
    charset='utf8'
)

cursor = conn.cursor()

#解释一下, 这是在操作hxx_test数据库中的my_first这张表

# 插入sql;
sql_insert = "insert into my_first (fds,fggtrh,qq,kkk) values (7,8,9,10)"
# 更新sql;
sql_update = "update my_first set qq = 99 where fds=33"
# 删除sql;
sql_delete = "delete from my_first where fds = 1"

# 把一个事务放到一个try块里，如果出现异常就回滚；
try:
    # 开启事务;
    conn.begin()

    cursor.execute(sql_insert)

    cursor.execute(sql_update)

    cursor.execute(sql_delete)

    # 确认提交;
    conn.commit()

except Exception as e:
    # 若有异常就回滚;
    conn.rollback()

cursor.close()
conn.close()

 

That database operations like this