Python连接mysql数据库及简单增删改查操作示例代码

#coding=utf-8
#连接数据库测试
import pymysql
#打开数据库
db = pymysql.connect(host="localhost",user="root",password="root",db="test")
#使用cursor()方法获取操作游标
cur = db.cursor()
#查询操作
sql = "select * from books"
try:
 # 执行sql语句
 cur.execute(sql) 
 results = cur.fetchall()
 #遍历结果
 for rows in results:
  id = rows[0]
  name = rows[1]
  price = rows[2]
  bookcount = rows[3]
  author = rows[4]
  print("id: {}, name: {}, price: {}, bookcount: {}, author: {}".format(id,name,price,bookcount,author))
except Exception as e:
 raise e
finally:
 db.close()

#coding=utf-8
#插入操作
import pymysql
db = pymysql.connect(host="localhost",user="root",password="root",db="test")
cur = db.cursor()
sql = """insert into books(id,bookname,price,bookCount,author) values (4,'三体',20,3,'刘慈欣')"""
try:
 cur.execute(sql)
 #提交
 db.commit()
except Exception as e:
 #错误回滚
 db.rollback()
finally:
 db.close()

#coding=utf-8
#更新操作
import pymysql
db = pymysql.connect(host="localhost",user="root",password="root",db="test")
# 使用cursor()方法获取游标
cur = db.cursor()
sql_update = "update books set bookname = '%s',author = '%s' where id = %d"
try:
 cur.execute(sql_update % ("边城","沈从文",4))
 #提交
 db.commit()
except Exception as e:
 #错误回滚
 db.rollback()
finally:
 db.close()

#coding=utf-8
#删除操作
import pymysql
db = pymysql.connect(host="localhost",user="root",password="root",db="test")
#使用cursor()获取操作游标
cur = db.cursor()
sql_delete = "delete from books where id = %d"
try:
 #向sql语句传递参数
 cur.execute(sql_delete % (1))
 #提交
 db.commit()
except Exception as e:
 #错误回滚
 db.rollback()
finally:
 db.close()