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