61. You are working in an online transaction processing (OLTP) environment. You realize that the salary for an employee, John, has been accidentally modified in the EMPLOYEES table. Two days ago, the data was in the correct state. Flashback logs gene…
http://www.appcoda.com/use-storyboards-to-build-navigation-controller-and-table-view/ Creating Navigation Controller in Storyboards Now let’s get our hands dirty and create our own Storyboards. In this tutorial, we’ll build a simple app that makes us…
当我第一次被分配到“修正执行ng lint语句后的错误”这项任务前,我就被导师提前告知这是一个很无聊的任务,当我开始后,我发现其实有一些办法可以加快这个无聊单调的工作.接下来,我就分享一下我的经验. 首先还是要来讲一讲 ng lint 的相关知识: 通过Angular CLI的执行语句 ng new XXX 创建新项目后,目录中会包含一个tslint.json文件,这个文件就是用来定义一个统一的代码风格. 有一些错误可以通过 ng lint -fix 自动解决,这个过程也许比较漫长.能自动修复的…
##Linear Regression with One Variable Linear regression predicts a real-valued output based on an input value. We discuss the application of linear regression to housing price prediction, present the notion of a cost function, and introduce the gradi…
mysql中You can't specify target table <tbl> for update in FROM clause错误的意思是说,不能先select出同一表中的某些值,再update这个表(在同一语句中). 如下l: 需要将select出的结果再通过中间表select一遍,就可以规避了错误. 如下: PS:这个问题只出现于mysql,sql service 和 oracle 不会出现此问题.…