import pymysql
# 封装数据库工具类
class DBUtil ( object ):
# 添加类属性
conn = None
@classmethod
def __get_conn ( cls ):
# 判断 conn 是否为空，如果是，创建
if cls . conn is None :
cls . conn = pymysql . connect ( host = "" , port = , user = "" ,
password = "" , database = "" , charset = "utf8" )
# 返回 非空连接
return cls . conn
@classmethod
def __close_conn ( cls ):
# 判断，conn 不为空，需要关闭。
if cls . conn is not None :
cls . conn . close ()
cls . conn = None
# 常用方法：查询一条结果
@classmethod
def select_one ( cls , sql ):
cursor = None
res = None
try :
# 获取连接
cls . conn = cls . __get_conn ()
# 获取游标
cursor = cls . conn . cursor ()
# 执行 查询语句
cursor . execute ( sql )
# 提取一条结果
res = cursor . fetchone ()
except Exception as err :
print ( " sql 错误： " , str ( err ))
finally :
# 关闭游标
cursor . close ()
# 关闭连接
cls . __close_conn ()
# 返回查询sql执行的 结果，
return res
# 常用方法：增删改
@classmethod
def uid_sql ( cls , sql ):
cursor = None
try :
# 获取连接
cls . conn = cls . __get_conn ()
# 获取游标
cursor = cls . conn . cursor ()
# 执行 uid 语句
cursor . execute ( sql )
print ( " 影响的行数： " , cls . conn . affected_rows ())
# 提交事务
cls . conn . commit ()
except Exception as err :
# 回滚事务
cls . conn . rollback ()
print ( " 增删改 SQL 失败： " , str ( err ))
finally :
# 关闭游标
cursor . close ()
# 关闭连接
cls . __close_conn ()
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