<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[ax478的博客]]></title><description><![CDATA[与其停在原地迷茫无所事事，不如在键盘上飞舞敲敲代码]]></description><link>https://blog.youkuaiyun.com/ax478</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; ax478]]></copyright><item><title><![CDATA[【SQL】CASE WHEN语句]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/97390176</link><guid>https://blog.youkuaiyun.com/ax478/article/details/97390176</guid><author>ax478</author><pubDate>Fri, 26 Jul 2019 15:11:57 +0800</pubDate><description><![CDATA[本文为个人学习笔记，材料取自leetcode

CASE WHEN语句可用于流程控制。
CASE有两种格式：简单CASE与CASE搜索函数
--简单Case函数
CASE sex
WHEN '1' THEN '男'
WHEN '2' THEN '女'
ELSE '其他' END
 
--Case搜索函数 
CASE WHEN sex = '1' THEN '男' 
WHEN sex = '2' ...]]></description><category></category></item><item><title><![CDATA[【SQL】GROUP BY语句]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/97375217</link><guid>https://blog.youkuaiyun.com/ax478/article/details/97375217</guid><author>ax478</author><pubDate>Fri, 26 Jul 2019 11:36:46 +0800</pubDate><description><![CDATA[本文为个人学习笔记，材料取自牛客网在线编程

GROUP BY语句通常用于结合sum()函数，根据一个或多个列对结果集进行分组。
例题：
题目描述
按照dept_no进行汇总，属于同一个部门的emp_no按照逗号进行连接，结果给出dept_no以及连接出的结果employees
CREATE TABLE dept_emp (
emp_no int(11) NOT NULL,
dept_no ch...]]></description><category></category></item><item><title><![CDATA[【SQL】ORDER BY语句及substr函数]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/97371715</link><guid>https://blog.youkuaiyun.com/ax478/article/details/97371715</guid><author>ax478</author><pubDate>Fri, 26 Jul 2019 10:40:14 +0800</pubDate><description><![CDATA[本文为个人学习笔记，材料取自牛客网在线编程

ORDER BY语句用于根据指定列（字段）对结果集进行排序，默认为升序，使用DESC关键字可以改为降序。
例题：
题目描述
获取Employees中的first_name，查询按照first_name最后两个字母，按照升序进行排列
CREATE TABLE employees (
emp_no int(11) NOT NULL,
birth_date...]]></description><category></category></item><item><title><![CDATA[【SQL】LIMIT子句]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/97276983</link><guid>https://blog.youkuaiyun.com/ax478/article/details/97276983</guid><author>ax478</author><pubDate>Thu, 25 Jul 2019 17:47:32 +0800</pubDate><description><![CDATA[本SQL系列为学习笔记，材料取自于牛客网在线编程


LIMIT子句可用于限制SELECT语句返回的行数。
直接看例题：
题目描述
分页查询employees表，每5行一页，返回第2页的数据
CREATE TABLE employees (
emp_no int(11) NOT NULL,
birth_date date NOT NULL,
first_name varchar(14) NOT ...]]></description><category></category></item><item><title><![CDATA[Git常用命令]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80841212</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80841212</guid><author>ax478</author><pubDate>Thu, 28 Jun 2018 11:59:58 +0800</pubDate><description><![CDATA[(lry_adminGetUserInfo)
$ git checkout develop
Switched to a new branch 'develop'
Branch 'develop' set up to track remote branch 'develop' from 'origin'.

(develop)
$ git pull
Already up to date.

(dev...]]></description><category></category></item><item><title><![CDATA[Git pull]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80776094</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80776094</guid><author>ax478</author><pubDate>Fri, 22 Jun 2018 16:59:22 +0800</pubDate><description><![CDATA[git add . ：他会监控工作区的状态树，使用它会把工作时的所有变化提交到暂存区，包括文件内容修改(modified)以及新文件(new)，但不包括被删除的文件。即提交新文件(new)和被修改(modified)文件，不包括被删除(deleted)文件

$ git add .

提交本地分支

$ git commit -m 'lry'
[master 50f8f84] lry


$ gi...]]></description><category></category></item><item><title><![CDATA[Git pull——取分支整合]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80744165</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80744165</guid><author>ax478</author><pubDate>Wed, 20 Jun 2018 11:51:21 +0800</pubDate><description><![CDATA[检查分支

$ git checkout -b lry
Switched to a new branch 'lry'
M       pom.xml
M       src/main/resources/application.properties




$ git status
On branch lry
Changes not staged for commit:
  (use &amp;quot;git a...]]></description><category></category></item><item><title><![CDATA[Git仓库克隆]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80742015</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80742015</guid><author>ax478</author><pubDate>Wed, 20 Jun 2018 09:51:39 +0800</pubDate><description><![CDATA[设置ssh公钥

# 这里点三次回车，默认确认就行了
$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/pc/.ssh/id_rsa):
/c/Users/pc/.ssh/id_rsa already exists.
Overwrite (y/n)?
...]]></description><category></category></item><item><title><![CDATA[UML类图几种关系的总结]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80681001</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80681001</guid><author>ax478</author><pubDate>Wed, 13 Jun 2018 16:30:06 +0800</pubDate><description><![CDATA[转载自UML类图几种关系的总结 
在UML类图中，常见的有以下几种关系: 泛化（Generalization）, 实现（Realization），关联（Association)，聚合（Aggregation），组合(Composition)，依赖(Dependency)

1. 泛化（Generalization）

【泛化关系】：是一种继承关系，表示一般与特殊的关系，它指定了子类如何特化父类的所...]]></description><category></category></item><item><title><![CDATA[spring boot入门 -- spring boot + Thymeleaf开发web项目]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80662467</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80662467</guid><author>ax478</author><pubDate>Tue, 12 Jun 2018 10:57:59 +0800</pubDate><description><![CDATA[“Spring boot非常适合Web应用程序开发。您可以轻松创建自包含的HTTP应用。web服务器采用嵌入式Tomcat，或者Jetty等。大多数情况下Web应用程序将使用spring-bootstarter-web模块快速启动和运行。”

本例子通过显示用户列表展示如何使用spring boot和Thymeleaf开发web项目。

几点说明：


Spring boot开发web项目，通常打...]]></description><category></category></item><item><title><![CDATA[spring boot入门 -- 介绍和第一个例子]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80660562</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80660562</guid><author>ax478</author><pubDate>Tue, 12 Jun 2018 09:13:16 +0800</pubDate><description><![CDATA[“越来越多的企业选择使用spring boot 开发系统，spring boot牛在什么地方？难不难学？心动不如行动，让我们一起开始学习吧！”

使用Spring boot ，可以轻松的创建独立运行的程序，非常容易构建独立的服务组件，是实现分布式架构、微服务架构利器。Spring boot简化了第三方包的引用，通过提供的starter，简化了依赖包的配置。



Spring boot的优点


...]]></description><category></category></item><item><title><![CDATA[Tomcat的下载与安装以及配置到Eclipse中]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80591797</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80591797</guid><author>ax478</author><pubDate>Wed, 06 Jun 2018 10:49:53 +0800</pubDate><description><![CDATA[
                    
                为了Java Web的开发，下面我们来安装一下Tomcat服务器，并将其配置在Eclipse中，前提是Eclipse已经安装完毕并可以正常使用，



一、Tomecat的下载与安装

1.首先从tomcat的官网下载适合自己操作系统的版本，网址http://tomcat.apache.org/download-90.cg...]]></description><category></category></item><item><title><![CDATA[python基础（六）——爬虫]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/80106455</link><guid>https://blog.youkuaiyun.com/ax478/article/details/80106455</guid><author>ax478</author><pubDate>Fri, 27 Apr 2018 12:44:57 +0800</pubDate><description><![CDATA[内容来源：雨敲窗python教程


  爬取糗事百科的段子


#_*_ coding: utf-8 _*_
import re
import requests
import html
import time

def crawl_joke_list(page = 1):
    url = &quot;https://www.qiushibaike.com/8hr/page/&quot; + str(page)
...]]></description><category></category></item><item><title><![CDATA[LeetCode第九题（Palindrome Number）]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79875174</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79875174</guid><author>ax478</author><pubDate>Tue, 10 Apr 2018 01:25:23 +0800</pubDate><description><![CDATA[Palindrome Number


  Determine whether an integer is a palindrome. Do this without extra space.


Some hints:

Could negative integers be palindromes? (ie, -1)

If you are thinking of converting the ...]]></description><category></category></item><item><title><![CDATA[LeetCode第八题（String to Integer (atoi)）]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79875151</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79875151</guid><author>ax478</author><pubDate>Tue, 10 Apr 2018 01:10:57 +0800</pubDate><description><![CDATA[String to Integer (atoi)


  Implement atoi to convert a string to an integer. 
  Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself w...]]></description><category></category></item><item><title><![CDATA[LeetCode第七题（Reverse Integer）]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79874912</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79874912</guid><author>ax478</author><pubDate>Tue, 10 Apr 2018 00:04:19 +0800</pubDate><description><![CDATA[Reverse Integer


  Given a 32-bit signed integer, reverse digits of an integer.


Example 1:

Input: 123
Output:  321

Example 2:

Input: -123
Output: -321

Example 3:

Input: 120
Output: 21


  Note...]]></description><category></category></item><item><title><![CDATA[LeetCode第六题（ZigZag Conversion）]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79860343</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79860343</guid><author>ax478</author><pubDate>Mon, 09 Apr 2018 01:24:45 +0800</pubDate><description><![CDATA[ZigZag Conversion


  The string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)


P  ...]]></description><category></category></item><item><title><![CDATA[python基础（五）——二叉树的实现]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79849947</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79849947</guid><author>ax478</author><pubDate>Sun, 08 Apr 2018 11:53:23 +0800</pubDate><description><![CDATA[class Node(object):
    def __init__(self, index):
        self.index = index
        self.left_child = None
        self.right_child = None
class BinarySearchTree(object):
    def __init__(self, root...]]></description><category></category></item><item><title><![CDATA[python基础（四）——读写文件]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79849909</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79849909</guid><author>ax478</author><pubDate>Sun, 08 Apr 2018 11:51:09 +0800</pubDate><description><![CDATA[#_*_ coding: utf-8 _*_
#写文件，先以w的格式打开文件（w即write，写），再writelines()写文件
f = open(&quot;c:/Users/47864/Desktop/2.txt&quot;, &quot;w&quot;)
f.writelines(&quot;read success\n&quot; + &quot;lkzlso&quot;)
f.close()
print(&quot;write success!&quot;)
#读文件，直接open...]]></description><category></category></item><item><title><![CDATA[python基础（三）——正则表达式]]></title><link>https://blog.youkuaiyun.com/ax478/article/details/79849893</link><guid>https://blog.youkuaiyun.com/ax478/article/details/79849893</guid><author>ax478</author><pubDate>Sun, 08 Apr 2018 11:49:54 +0800</pubDate><description><![CDATA[import re
#匹配abc
m = re.findall(&quot;abc&quot;, &quot;aabbccabccbaccbaaabcabc&quot;)
print(m)
#匹配一位数字，digit
m = re.findall(&quot;\d&quot;, &quot;123abc1a2b3c1b2c3a&quot;)
print(m)
#匹配四位数字
m = re.findall(&quot;\d\d\d\d&quot;, &quot;123abc1234ab12345c&quot;]]></description><category></category></item></channel></rss>