python3 连接数据库注意点

类库：pymysql

 '''
 Created on 2019年

 @author: Root
 '''
 import pymysql
 from name import getName
 # 数据库连接信息
 conn = pymysql.connect('localhost','root','root','myown',charset='utf8')
 # 错误写法： utf-8   UTF-8
 # 正确写法：utf8   UTF8
 # 创建游标
 cursor = conn.cursor()

 class DBUtils:

     # 新增数据
     def add(self):
         try:
             name = getName()
             sql = 'insert into test(name) values(%s)'
             cursor.execute(sql,name)
             conn.commit()
             print ('新增数据成功')
         except:
             conn.callback()
             print ('新增出错，事务回滚')

     # 查询数据
     def query(self):
 #         sql = "select * from test1"
         sql = "select count(1) from test"
         cursor.execute(sql)
 #         result = cursor.fetchone()
         result = cursor.fetchall()
         print (result)

     # 删除数据
     def delDate(self):
         sql = "delete from test1 where id = '%s';"
         try:
             cursor.execute(sql,2)
             conn.commit()
             print ('删除成功')
         except:
             conn.callback()
             print ('删除失败')
     # 修改数据
     def update(self):
         sql = 'update test1 set name = %s where id = %s;'
         try:
             cursor.execute(sql,('赵四',4))
             conn.commit()
             print ('数据更新成功')
         except Exception as e:
             print (e.getMessage())
             conn.callback()
             print ('数据更新失败')

 # for i in range(100000):
 #     DBUtils().add()

 DBUtils().query()
 # DBUtils().delDate()
 # DBUtils().update()

 conn.close()

注意点：

① 数据库连接信息写法：

1.     host='localhost',port=3306,user='root',passwd='root',db='myown',charset='utf8'
2.     host='localhost',port=3306,user='root',password='root',db='myown',charset='utf8'
3.     'localhost','root','root','myown',charset='utf8'

② 编码格式必须为:  utf8或者UTF8