Detailed introduction to MySQL adapter PyMySQL

This article mainly introduces the relevant information of the MySQL adapter PyMySQL in detail. It has certain reference value. Interested friends can refer to it.

In this article we introduce to you how to use PyMySQL to connect to the database in Python3. , and realize simple addition, deletion, modification and query.

What is PyMySQL?

PyMySQL is a library used to connect to the MySQL server in Python3.x version, and mysqldb is used in Python2.

PyMySQL follows the Python Database API v2.0 specification and includes the pure-Python MySQL client library.

PyMySQL Installation
Before using PyMySQL, we need to ensure that PyMySQL is installed.

PyMySQL Download

If it is not installed yet, we can use the following command to install the latest version of PyMySQL:

$ pip install PyMySQL

If your system The pip command is not supported. You can install it using the following methods:

1. Use the git command to download and install the installation package (you can also download it manually):

$ git clone https://github.com/PyMySQL/PyMySQL
$ cd PyMySQL/
$ python3 setup.py install

2. Database operation examples, directly upload the code.

import pymysql
import datainfo
import time

#获取参数

host = datainfo.host
username = datainfo.username
password = datainfo.password
database = datainfo.db

print()

#测试数据库连接
def testconnect():

 #打开数据库链接

 db = pymysql.connect(host,username,password,database)

 #使用cursor() 方法创建一个游标对象 cursor

 cursor = db.cursor()

 #使用execute()方法执行SQL查询

 cursor.execute("select version()")

 #使用fetchone ()获取单条数据

 data = cursor.fetchone()

 print(data)

 db.close()

#插入数据库
def InsertDate():
 #打开数据库链接

 db = pymysql.connect(host,username,password,database,charset='utf8')

 #使用cursor() 方法创建一个游标对象 cursor

 cursor = db.cursor()

 create_time = time.strftime('%Y-%m-%d %H:%M:%S')
 update_time = time.strftime('%Y-%m-%d %H:%M:%S')
 start_time = time.strftime('%Y-%m-%d %H:%M:%S')
 end_time = time.strftime('%Y-%m-%d %H:%M:%S')
 remark = "测试插入信息"
 print("开始")
 #Sql 插入语句
 sql = "insert into demo(start_time,end_time,creat_time,update_time,remark) " \
   "VALUES ('%s','%s','%s','%s','%s')"\
   %(start_time,end_time,create_time,update_time,remark)
 try:
  #执行sql
  print("执行插入")
  tt = cursor.execute(sql)
  print(tt)
  db.commit()
 except UnicodeEncodeError as e :
  #发生错误时回滚
  print(e)
  db.rollback()
 db.close()


#查询操作
def selectData():
 db = pymysql.connect(host, username, password, database, charset='utf8')

 # 使用cursor() 方法创建一个游标对象 cursor

 cursor = db.cursor()

 sql = "select * from demo where id >='%d'" %(1)
 try:
  #执行sql
  print("执行查询")
  cursor.execute(sql)
  results = cursor.fetchall()
  for row in results:
   id = row[0]
   start_time = row[1]
   end_time = row[2]
   create_time = row[3]
   update_time = row[4]
   remark = row[5]
   #打印结果
   print("id = %d,start_time=%s,end_time=%s,create_time=%s,update_time=%s,remark=%s" %(id,start_time,end_time,create_time,update_time,remark))

  db.commit()
 except UnicodeEncodeError as e :
  #发生错误时回滚
  print(e)

 db.close()

#更新操作
def update_data():
 db = pymysql.connect(host, username, password, database, charset='utf8')

 # 使用cursor() 方法创建一个游标对象 cursor

 cursor = db.cursor()
 update_time = time.strftime('%Y-%m-%d %H:%M:%S')
 sql = "update demo set update_time ='%s' where id >='%d' " %(update_time,1)
 try:
  #执行sql
  print("执行更新")
  cursor.execute(sql)

  db.commit()
 except UnicodeEncodeError as e :
  #发生错误时回滚
  print(e)
  db.rollback()
 db.close()

#删除操作
def delete_Date():
 db = pymysql.connect(host, username, password, database, charset='utf8')

 # 使用cursor() 方法创建一个游标对象 cursor

 cursor = db.cursor()

 sql = "delete from demo where id <&#39;%d&#39; " %(1)
 try:
  #执行sql
  print("执行删除")
  cursor.execute(sql)

  db.commit()
 except UnicodeEncodeError as e :
  #发生错误时回滚
  print(e)
  db.rollback()
 db.close()


if __name__ == &#39;__main__&#39;:
 testconnect()
 InsertDate()
 selectData()
 update_data()
 delete_Date()

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