<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[H_0521的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/H_0521</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; H_0521]]></copyright><item><title><![CDATA[postgreSQL语法]]></title><link>https://blog.youkuaiyun.com/H_0521/article/details/139113906</link><guid>https://blog.youkuaiyun.com/H_0521/article/details/139113906</guid><author>H_0521</author><pubDate>Wed, 22 May 2024 15:30:52 +0800</pubDate><description><![CDATA[(2) 字符串类型的数据原则上按字典的顺序排序，不能与数字的大小顺序混淆，如’1-3‘]]></description><category></category></item><item><title><![CDATA[Java面试题]]></title><link>https://blog.youkuaiyun.com/H_0521/article/details/126948157</link><guid>https://blog.youkuaiyun.com/H_0521/article/details/126948157</guid><author>H_0521</author><pubDate>Tue, 20 Sep 2022 11:10:48 +0800</pubDate><description><![CDATA[Java面试题]]></description><category></category></item><item><title><![CDATA[MySQL常用]]></title><link>https://blog.youkuaiyun.com/H_0521/article/details/112368241</link><guid>https://blog.youkuaiyun.com/H_0521/article/details/112368241</guid><author>H_0521</author><pubDate>Fri, 08 Jan 2021 16:27:17 +0800</pubDate><description><![CDATA[MySQL 常用
目录MySQL 常用一、截取二、类型转换

一、截取
1、left(str,length) 从左边截取length

2、right(str,length)从右边截取length

3、substring(str,index)当index&gt;0从左边开始截取直到结束  当index&lt;0从右边开始截取直到结束  当index=0返回空

4、substring(str,index,len) 截取str,从index开始，截取len长度

5、substring_index(str,]]></description><category></category></item><item><title><![CDATA[java生成UUID]]></title><link>https://blog.youkuaiyun.com/H_0521/article/details/108994305</link><guid>https://blog.youkuaiyun.com/H_0521/article/details/108994305</guid><author>H_0521</author><pubDate>Sat, 10 Oct 2020 11:49:56 +0800</pubDate><description><![CDATA[java生成UUID
1.生成UUID
import cn.hutool.core.util.IdUtil;

public class IdUtilTest{
    public static void main(String[] args) {
        //获取随机UUID
        System.out.println(IdUtil.randomUUID());
        //简化的UUID，去掉了横线
        System.out.println(IdUtil.simp]]></description><category></category></item></channel></rss>