Tag:Key value

  • Operation commands for hash type in redis


    1、 Redis hash (hash) Redis hash is a mapping table of field and value of string type. Hash is especially suitable for storing objects. Each hash in redis can store 232 – 1 key value pairs (more than 4 billion). Simple example:> HMSET runoobkey name “redis tutorial” description “redis basic commands for caching” likes […]

  • What is the difference between the type column and the extra column of the MySQL execution plan in the game?


    1、 Interpretation typeThe type of the execution plan indicates the access data type. There are many access types. 1、systemThis means that only one row of data is returned in this step. If the execution object of this step is a driver table or main table, the driven table or sub query is accessed only once. […]

  • Study of project.pbxproj file


    (this article)articleIt was originally published on CSDN, but now the blog is migrated and rearranged and modified with markdown) Because of the needs of the project, I recently learned project.pbxproj. There are a lot of information about the introduction of this document on the Internet, but I don’t feel very detailed. Here I make a […]

  • Reading redis source code — dict (11)


    dict Redis dictionary uses hash table as the underlying implementation. There can be multiple hash table nodes in a hash table, and each hash table node stores a key value pair of the dictionary. /* Hash Tables Implementation. * * This file implements in-memory hash tables with insert/del/replace/find/ * get-random-element operations. Hash tables will auto-resize […]

  • Skin changing function, three sets of colors are prepared in CSS file


    1. Knowledge points 1.document.documentElement //Method to get HTML (document. Documentelement) //Document.documentelement is specifically used to get the HTML tag document.documentElement.setAttribute(‘data-skin’, key) Effect picture: when key = “white” 2.: root selector Definition and usage:: the root selector matches the document root element.In HTML, the root element is always an HTML element. 3. Storage localstorage The value […]

  • ThinkPHP 5 model usage history – global definition


    Series articles: ThinkPHP 5 model usage history – inherit first and then extend ThinkPHP 5 model usage history – replication ThinkPHP 5 model usage history – global definition ThinkPHP 5 model usage history – ide friendly ThinkPHP 5 model usage history – Single Responsibility ThinkPHP 5 model usage history – sorting code ThinkPHP 5 model […]

  • Dictionary in Python


    By Ankit GuptaCompile VKSource: towards Data Science In this article, I will discuss dictionaries. This is the second article in the “data structures in Python” series. The first part of this series is about lists. Dictionaries are important data structures for indexing with keys in Python. They are an unordered sequence of items (key value […]

  • C # solve the Chinese garbled code of httplistener querystring and returned JSON Chinese format


    Solution to httplistener querystring Chinese garbled Code: When the request arrives, get the request. URL and return the get request parameter key value pair public class RequestHelper { public static Dictionary<string, string> EncodeQueryString(Uri uri) { var ret = new Dictionary<string, string>(); var q = uri.Query; if (q.Length > 0) { foreach (var p in q.Substring(1).Split(‘&’)) […]

  • Kafka message store overview


    abstract As a message middleware system, Kafka faces the primary problem of how to persist messages and how to read, write and parse them conveniently. This article will start with Kafka’s message storage, and then explain the important code parts one by one. Kafka’s message concept, first of all, we are not talking about messages […]

  • Some simple usage of redis cache in springboot


    1. Import redis dependencies <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> 2. Configure redis in application.properties #Redis configuration #Redis server address spring.redis.host= #Redis server connection port spring.redis.port=6379 #Redis database index (0 by default) spring.redis.database=0 #Maximum number of connections in the connection pool (negative value indicates no limit) spring.redis.jedis.pool.max-active=50 #Maximum blocking wait time of connection pool (negative value indicates […]

  • Cannot index is null and is not null in MySQL?


    Cannot index is null and is not null in MySQL? I don’t know why or when. There is a popular saying in the Jianghu that MySQL query conditions include is null, is not null,! = like %* 、like %*%,NoUsing index queries,can onlyUse full table scan. When I first entered the industry, I thought so, and […]