• dataguard ORA-12514: TNS:listener does not currently know of service requested in connect descriptor


    The meaning of the error is that the listener does not know the request service in the connection resolver. Here we will talk about static listening and dynamic listeningDynamic registration means that when instance is started, the PMON process dynamically registers the instance and service to the listener according to the two parameters of instance […]

  • [video tutorial] package manager installation: a new way to use openresty


    Openresty is a scalable web platform realized by extending nginx with Lua, which integrates a large number of sophisticated Lua libraries, third-party modules and most dependencies.It is used to easily build dynamic web applications, web services and dynamic gateways that can handle ultra-high concurrency and high scalability.The function is similar to nginx, because it supports […]

  • Creating SQL statements dynamically for Oracle and MySQL


    MYSQL: @Query(value = “select * from project_demand where project_id=?1 and if(?2!=”,demand_id in (select demand_id from demand_user where user_id=?2),1=1)”,nativeQuery = true) If (? 2! = ‘, demand_id in (select demand_ Oracle: DECODE(VALUE,IF1,THEN1,IF2,THEN2,IF2,THEN2,..,ELSE) Indicates that if the value is equal to IF1, the result of the decode function returns then1,… Or else if it is not equal […]

  • Dynamic data sources that can be increased or decreased at runtime


    At present, there is a service in the company’s project that provides dynamic indicator calculation. You can check different SQL or code configurations in different databases and calculate indicators in real time. Originally, the data source needs to be re configured. If you think about it, you can add or delete it without re starting […]

  • JQuery add input box dynamically


    There are two ways for jQuery to dynamically add input boxes. 1. Display page <!DOCTYPE html> <html lang=”en”> <head> <meta charset=”UTF-8″> <meta http-equiv=”X-UA-Compatible” content=”IE=edge”> <meta name=”viewport” content=”width=device-width, initial-scale=1″> < title > dynamically add input box < / Title > <!–<link href=”assets/font-awesome/css/font-awesome.css” rel=”stylesheet” />–> <!–[if lt IE 9]> <script></script> <script></script> <![endif]–> </head> <body> <h1>Add input box […]

  • Fundamentals of python (1)


    1. Foundation type Python data types can be divided into two types: one is built-in, and the other is in other packages. The built-in data types can be divided into 10 types: (1) integer Represented by int, cast function is int(): x = 10 print(x) int(10.88) The output is all 10 (2) real numbers In […]

  • Leetcode’s HOT100 series — 62. Different paths — simple dynamic planning


    The topic is relatively clear, in short: A B C D E F G H I J K L You can only go right or down from a to L. there are several ways to go.Here we use the method of dynamic planning to do it.The most important thing of dynamic programming is dynamic equation. […]

  • HOT100 series of leetcode — 64. Minimum path sum — dynamic planning with minimum weight


    If this:HOT100 series of leadcode — 62. Different paths — simple dynamic planning If you understand, the question is basically the same,The differences are:1. Here, each path is equivalent to one more weight2. The conclusion is no longer fixed, but to compare which weight is smaller in different walking methods For the first point, the […]

  • C dynamic dynamic type and anonymous class


    To show respect for the original author, first post the original link: https://www.cnblogs.com/hnsongbiao/p/8250956.html Here is the text:   Dynamic typeSimple example Dynamic expando = new system. Dynamic. Expandoobject(); // dynamic type fields are readable and writable expando.Id = 1; expando.Name = “Test”; String JSON = utils. Convertjson. Jsonencode (expando); // output {ID: 1, name: ‘test’} […]

  • [Objective-C] the dynamics of Objective-C


    The dynamic of Objective-C is mainly reflected in the following three aspects (1) dynamic type: determines the type of object at runtime. (2) dynamic binding: the method to determine the object at runtime. (3) dynamic load: load the required resources or code modules at runtime. I. dynamic type Dynamic type refers to the dynamic nature […]

  • ThinkPHP + layui stream loading implementation


    html JS, to introduce layui.js layui.use(‘flow’, function() { var $ = layui.jquery; var flow = layui.flow; flow.load({ Elem: ‘container’ // stream load container //The element where the scroll bar is located is generally not required to be filled in. This is just for demonstration purposes. , done: function (page, next) {// execute the callback on […]

  • How does JavaScript work?


    Abstract:Understand JS execution principle. Original: how does JavaScript work? Author: hengg Fundebug is reprinted by authorization, and the copyright belongs to the original author. What is JavaScript? Let’s confirm the definition of javascript: Javascript is an interpretive dynamic language. Interpretative languages exist relative to compiled languages. The source code is not directly compiled into the […]