• Nesting of single quotation marks in SQL statements


    In SQL statements, we will inevitably use single quotation mark nesting, but direct nesting is certainly not OK. It is also not OK to use backslash as escape character in Java, and single quotation mark is used as escape character in SQL. For example, the following example is an example of a query in a […]

  • JavaScript promise says goodbye to asynchronous random nesting


    What is promise? Before we talk about promise, we have to say that JavaScript has nested callback functions In JavaScript language, whether it’s writing all kinds of event callbacks, AJAX callbacks, or business logic on node.js, the problem we have to face is all kinds of callback functions. Callback functionLess is good, once more and […]

  • Summary of the use of react


    Recent projects use react(react+redux+react-router(v4)+react-router-redux(v5-alpah.6)+react-router-config(v1-beta.4))To develop the website, we encountered some problems in the process of using, and also raised many problems in SG, such as: how to monitor the routing switch? Component will receive props render dead loop? Route nested routing leads to problems and so on, interested can directly open my problem to see. […]

  • What are the format types of JSON?


    JSON is the most popular data exchange format at present. For it, we need to be very familiar with all aspects of its knowledge. This time, let’s take a look at its format types. Data exchange format Basic types Array type Object nesting Case practice Basic types {“key”: value, “key”: “value”,…}, start with braces, add […]

  • Fatal error c1045: compiler restriction: link specification nested too deeply


    preface I believe you have come here through search engines with the same problem. In order not to delay the time of troubleshooting, I would like to explain the problem areas described in this article in advance My problems are related to C + + templates; If I reduce the parameters passed, it is possible […]

  • Simple encapsulation of react routing


    premise Understanding the react framework Familiar with JSX syntax Have the foundation of react router DOM plug-in React route encapsulation Create a new router folder under the SRC directory of react project, and create index.js and config.js under the router file directory Router / config.js — generate and throw the routing configuration table //Introduce route […]

  • Using swiper in react framework


    premise Grasp the foundation of react Experience of using swiper carousel plug-in Use process of react + swiper Download the swiper plug-in NPM install swiper – s in react project Introducing swiper into react component import Swiper from ‘swiper’ import ‘swiper/css/swiper.css’ Three layer nested structure of HTML generated from react component <div className=’swiper-container’> <div className=’swiper-wrapper’> […]

  • Explanation and solution of uncaught (in promise) navigationduplicated: avoided redundant navigation to current location: “/ xxx”. At createroutererror


    Error description Uncaught (in promise) NavigationDuplicated: Avoided redundant navigation to current location: “/xxx”. at createRouterErrorThis error means that a duplicate definition of navigation is captured in promise, because the programmed navigation is used for routing jump,$router.pushMethod returns a promise object. It’s repeated herepushThe same routing address was found, so this error was reported.Sometimes it’s a […]

  • JS using bucket is simple and convenient to realize synchronous loading


    scene All interfaces need to be loaded before processing Need to optimize multiple http / IO interface nesting to slow down performance Multiple tasks need to be completed before processing callback Look at the code /* *No data bucket (for synchronous load callback only) */ function pail(len) { return { len: len, num: 0, t_fun: […]

  • Explain Python Google protocol buffer in detail


    This article mainly introduces how to use Google protocol buffer in Python language (later abbreviated as Pb), including the following parts: Why use PB? Install Google PB Custom. Proto file Compile. Proto file Parsing the target py file serialization and deserialization More complex message Dynamic compilation Why use PB? Pb (protocol buffer) is a structured […]

  • Flutter customscrollview control


    Lao Meng‘s Guide: Happy 51 holiday is over, switch to effort mode. Today, I’d like to share with you the customscrollview component, which will be often used in future projects. Customscrollview is like an adhesive, which can glue multiple components together with a unified rolling effect. CustomScrollView Customscrollview is a scrolling component that uses the […]

  • Hacking with angular: how to get different levels of $Index in deep nested ngrepeat


    usengRepeatWhen we give instructions, we usually pass them$indexGet the index of each cycle in the current level, but we will still use it when there is an array (array a) in the data we cyclengRepeatLet’s loop through this array. But at this time, if we still need the index of each item in array a […]