• Django + uni app realizes cross domain request in data communication


    In the mode of separation of front end and back end, Django restframework is used in the back-end, and uni app is used in the front-end for app development.Front end code: Django back end cross domain configurationsettings.py Add:INSTALLED_APPS = [ ‘corsheaders’, ] Add in middleware ‘corsheaders.middleware.CorsMiddleware’, #Note that the order must be in front of […]

  • Analysis of 1z0-062 question bank 3


    Title:The hr user executes the following query on the employees table but does not issue commit, rollback, or any data definition language (DDL) command after that: SQL> SELECT job FROM employees WHERE job=’CLERK’ FOR UPDATE OF empno; HR then opens a second session. Which two operations wait when executed in HR’s second session? A.INSERT INTO […]

  • Spring framework Foundation (06): introduction of MVC architecture mode and detailed explanation of execution process


    This article source code: GitHub · point here | gitee · point here 1、 Introduction to springmvc framework 1. MVC design concept MVC is a kind of software design paradigm. It organizes code by separating business logic, data and interface display, and integrates business logic into one component. While improving and personalizing interface and user […]

  • How to implement IOS intrusion free buried point scheme?


    In the process of development, embedded point can solve two kinds of problems: one is to understand the user’s behavior of using app, the other is to reduce the difficulty of analyzing online problems. At present, the common embedding methods in IOS development mainly include: Code embedding point Visual buried point No buried point Code […]

  • [pl / SQL] NVL, nvl2 and coalesce


    After reading this chapter, you will learn the following: Their respective usage What’s different about them NVL function The functions of NVL (E1, E2) are as follows:If E1 is null, the function returns E2, otherwise it returns E1 itself Example: if the comm bonus on EMP table is null, replace it with 0 SELECT NVL(COMM,0) […]

  • Scrollview, collectionview and tableview add uirefreshcontrol to achieve drop-down refresh


    Apple addedUIRefreshControl, but only inUITableViewControllerCannot be used inUIScrollViewandUICollectionViewIn the. New features of IOS 10 Starting with IOS 10,UIScrollViewAdded onerefreshControlProperty, which is used to set theUIRefreshControlAssign a value to the property so thatUIScrollViewThere is a drop-down refresh function. And beforeUITableViewControllerNo settings are requiredUIRefreshControlOfframe, just configureUIRefreshControl。 becauseUITableViewandUICollectionViewInherited fromUIScrollView, soUITableViewandUICollectionViewAlso inheritedrefreshControlProperty, that is, refresh control can be easily […]

  • Details of create view and usage restriction instance of MySQL view


    The example of this article describes the creation view and usage limitation of MySQL view. To share with you for your reference, as follows: After MySQL 5. X, database views are supported. In mysql, almost the features of views meet the SQL: 2003 standard. MySQL processes queries on views in two ways: First, MySQL creates […]

  • WPF: data binding summary (1)


    1、 Concept: what is data binding? Data binding in WPF: it is the process of establishing connection between application UI and business logic;Extension: Provides a simple and consistent way for applications to represent and interact with data. Elements can be bound to data in various data sources in the form of common language runtime (CLR) […]

  • WPF: simple selection of image display function under the directory


    Load the pictures in the directory and select Show The functions are as follows: Select directory, load pictures Choose a picture to show Difficulties: Select the directory under WPF and load it into the collection Bind to collection current item Main ideas and key codes:A data template class, photo, is simpler to use the bitmapframe […]

  • IOS knowledge combing – UI (I) rendering & touch


    Take a look at the IOS UI. There are several important concepts related to IOS UI: window, viewcontroller, view, layer. First of all, we need to know that in these concepts, the core layer of UI presentation, all the information that determines the final presentation is on the layer. View is a direct encapsulation of […]

  • Springboot & & A Case Study of front and back end separation of Vue


    Springboot & & A Case Study of front and back end separation of Vue 1. Recently, I’ve been learning the relevant content of springboot. I don’t want to learn it for the time being. I just searched the Internet and found that the front and back of everyone’s discussion were separated. Out of curiosity, I […]