• Oracle — window function (2)


    Today I’ll talk about how some rank functions use window functions. RANK() OVER ( query_partition_clause ORDER_BY clause) DENSE_RANK( ) OVER ( query_partition_clause ORDER_BY clause ) Example hold scott.emp The table is partitioned according to “deptno”, and then ranked according to “Sal” in the partition. Let’s look at rank first. SQL> conn scott/triger; It’s going to […]

  • Three level linkage of picker in uni app wechat applet


    I have done a three-level linkage function of picker before. Here is the code to share with you Specific code: // An highlighted block {{ areaname }} {{ buildingname }} {{ floorname }} import Vue from ‘vue’; export default { data() { return { Multiarray: [[‘1 ‘,’2’,’3 ‘,’4’,’5 ‘,’6’,’7 ‘], [‘1 house’, ‘2 house’, ‘3 […]

  • Springboot + hikaricp + dropwizard metrics statistics connection pool usage


    Springboot + hikaricp + dropwizard metrics statistics connection pool usage Background: hikaricp is the most widely used connection pool tool class in Java. Springboot also uses this by default. Now I want to get the usage of connection pool. Let’s assume that springboot has integrated hikaricpone pom.xml Add the dropwizard metrics configuration io.dropwizard.metrics metrics-core io.dropwizard.metrics […]

  • Programmer or coder


    Fat Sir: soldier, I’ll tell you something different today. Listen to me Chief: OK, what do you say Fat Sir: you don’t talk Imagine a scene. Situation one Have you ever met such a person in your work? Only do the things you arranged for him, and after that, you will not think about how […]

  • How to analyze complexity from the worst, average and best?


    This article is included in the album:http://dwz.win/HjK preface Every day, brother Tong is a hard core man. In the last section, we were engaged in the transition from post statistical method to asymptotic analysis method, and explained in detail how to analyze the complexity of the algorithm. However, if we follow the strict asymptotic analysis […]

  • Translate numbers into strings | Python


    Translate numbers into strings Title Source: leetcode https://leetcode-cn.com/problems/ba-shu-zi-fan-yi-cheng-zi-fu-chuan-lcof subject Given a number, we translate it into a string according to the following rules: 0 into “a”, 1 into “B” 11 to “L” 25 to “Z”. A number may have multiple translations. Please program a function to calculate how many different translation methods there are for […]

  • Use Tencent’s official wechat domain name detection API interface to monitor whether the domain name is blocked in wechat


    backgroundDue to the strict restrictions on wechat, domain names can easily be judged as follows: 1. Induced sharing 2. Non official wechat website 3. Webpage contains malicious and fraudulent content 4. Access to the page has stopped 5. To browse, press and hold copy browser to open 6. Others and so on! After the emergence […]

  • Find the complete string of permutation


    Today to share a simple algorithm problem–Find the complete string of permutation I believe many people will be tested by this question, and many people can’t write it. Relax. Next, let’s see how to realize this question. First, let’s look at what the problem is. Given a string, find out all possible permutations and combinations […]

  • [20210219] full table scan logic read problem.txt


    [20210219] full table scan logic read problem.txt –//General inquiry logic reading settings_ trace_ pin_ Time, or set 10200 events–//Settings_ trace_ pin_ One obvious disadvantage of time is that it is set at the system level and needs to be restarted, so that each process generates a lot of trace information–//Another factor is that for the […]

  • Analysis of datetime type conversion from datetime set in SQL Server


    In SQL server, you need to pay special attention to the conversion of data type DateTimeOffset to datetime type or datetime2 type. If you are not careful, you may encounter the following situation. Let’s construct a simple case to simulate the situation you may encounter.   CREATE TABLE TEST (     ID                 INT IDENTITY(1,1)    ,CREATE_TIME        DATETIME […]

  • A simple performance test of JS regular expression


    Recently, we use js to do some text processing, which inevitably involves regular expressions. Because the size of the text will reach GB level, speed and efficiency are still very critical. according tojsperfThe test on found that if you need to use regular to match, it is a precompiled expressionprecompiled searchThe best performance. This is […]

  • Trust learning — match control flow operator


    Rust has a very powerful control flow operator called match, which allows us to compare values with a series of patterns and then execute code based on the matching patterns. Patterns can consist of literal values, variable names, wildcards, and many other things.I feel the same as switch in JS~^~ The tutorial of trust, which […]