错误笔记：在OleDb执行下Access ，程序不报错，但是Update也更新不成功的

http://blog.sina.com.cn/s/blog_4668898b010008io.html（ OLEDB传递参数给Access要注意的问题）

代码     string sql = @"update UserInfo set 
[RoleID] = @RoleID,
[UserName] = @UserName,
[PWD] = @PWD,
[Email] = @Email
where [UserIdentity] = @UserIdentity ";

            DbCommand cmd = dbHelper.GetSqlStringCommond(sql
                );
            dbHelper.AddParameterCollection(cmd,
                new OleDbParameter("UserIdentity", user.UserIdentity),//注意UserIdentity放置位置
                new OleDbParameter("RoleID", user.RoleID),
                new OleDbParameter("UserName", user.UserName),
                new OleDbParameter("PWD", user.PWD),
                new OleDbParameter("Email", user.Email)
                 
                );

      
修改后的Code（运行成功）：

代码 string sql = @"update UserInfo set 
[RoleID] = @RoleID,
[UserName] = @UserName,
[PWD] = @PWD,
[Email] = @Email
where [UserIdentity] = @UserIdentity ";

            DbCommand cmd = dbHelper.GetSqlStringCommond(sql
                );
            dbHelper.AddParameterCollection(cmd,
                
                new OleDbParameter("RoleID", user.RoleID),
                new OleDbParameter("UserName", user.UserName),
                new OleDbParameter("PWD", user.PWD),
                new OleDbParameter("Email", user.Email),
                new OleDbParameter("UserIdentity", user.UserIdentity)//注意UserIdentity放置位置
                 
                );