sqlite創建數據庫時一定要嚴格，尤其是空格不能忘記

如：String sql = "create table " + TABLE_NAME + "(" + id
+ " integer primary key, " + mac + " varchar(50), " 
+ flag + " interger, "

+ num+ " interger);";

前一個分號後有一個空格再輸入類型