• Vue Router: understanding routing


    Understanding routing Routing is used to set access path and map path and component In the single page application of Vue router, the change of page path is the switch of composition Back end Routing: the back end processes the mapping relationship between URL and pageFront end Routing: front end manages the mapping relationship between […]

  • Three steps of SQL optimization


    One day, the development students reported that there was a very full SQL in the online business database, and it took almost one minute to finish each time. I hope we can help optimize it. The specific SQL is as follows: SQL optimization step 1 – view execution plan For a SQL optimization, our first […]

  • Spring MVC request processing. Your answer is guaranteed to pass the interview!


    The spring version used in this article is 5.2.2.release Nine components Almost all the functions of spring MVC are completed by nine components, so it is very important to understand the role of the nine components for learning spring MVC. /**File upload parser*/ private MultipartResolver multipartResolver; /**Region parser for Internationalization*/ private LocaleResolver localeResolver; /**Topic parser*/ […]

  • Summary of Oracle common views


    1. Dynamic performance view of database / instancev$database :displays information about the database from the control file.V $instance: displays the state of the current instanceV $option: displays Oracle database options and features        Option must be separately licensed        whereas features come with the product and are enabled based on         The product that is runningv$parameter :displays information […]

  • Review of SQL Sever basic command


    catalogue preface Installation of virtual machine Commands and operations Basic command syntax Case sensitive SQL keyword and function name Column and Index Names alias Too long to see? Space Database connection Connection of SSMS Connection of command line Database operation establish delete constraint integrity constraint Common constraints NOT NULL UNIQUE PRIMARY KEY FOREIGN KEY DEFAULT […]

  • How to implement a custom drop-down menu with animation effect


    When we set the receiving address in the shopping app, there will be drop-down menu items for us to select provinces and cities. Today I’m going to use Android nativeSpinnerControl to achieve a custom drop-down menu function, and with a transparent gradient animation effect. The functions and ideas are as follows: The drop-down menu style […]

  • Performance tuning of gaussdb (DWS) (2): bad taste SQL recognition


    abstract: we call the “bad smell” in SQL the SQL statements that lead to inefficient execution and their execution methods. What is the bad taste in SQL SQL language is the standard language of relational database (RDB). Its function is to translate the user’s intention into a language that the database can understand. When human […]

  • Oracle foundation 2: three paradigms of Oracle view, user management, sequence, DML, transaction, index and database design


    1、 View 1. View, also known as virtual table, does not occupy physical space. This is also a relative concept, because the definition statement of view itself should be stored in the data dictionary. Views have only logical definitions.Every time you use it, you just re execute SQL。2. Views are obtained from one or more […]

  • Programming architecture (08): spring.mvc.boot framework


    Source code:GitHub. Click here || Gitee. Click here 1、 Spring framework 1. Framework overview Spring is an open source framework. One of the main advantages of the framework is its layered architecture, which allows users to choose which component to use and provides an integrated framework for J2EE application development. Spring uses basic JavaBeans to […]

  • Building SSM project: using the framework spring MVC mybatis


    buildCreate a maven projectAdd dependency: you can choose to add it according to your own needs <dependencies> Spring related configuration and integration mybatis related configuration: applicationcontext.xml <? xml version=”1.0″ encoding=”UTF-8″?> Web.xml related configuration <web-app xmlns:xsi= ” http://www.w3.org/2001/XMLSchema-instance ” xmlns=” http://java.sun.com/xml/ns/javaee ” MVC related configuration, configuration view parser, configuration includes JSP view parser configuration, but also […]

  • Basic SQL statements


    Table structure Experiment content 1 Create a database cap with SQL statements. The data file name is capdata.mdf. The initial storage space of the data file is 50m, the maximum storage space is 500m, and the automatic growth of the storage space is 10m. CREATE DATABASE CAP ON ( NAME = CAP, File name =’c:: […]

  • Weekly report of IOS open source project 1222


    fromOpenDigg  The second issue of IOS open source project weekly is coming. Our IOS open source weekly collects the high-quality open source projects of IOS development newly collected by opendigg in the past week, which is convenient for IOS developers to find the project tools they need. ios-ossKickStarter’s open source IOS app TinyConsoleA small log […]