<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[u011925590的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/u011925590</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; u011925590]]></copyright><item><title><![CDATA[mysql-单张表查询各科成绩前两名的记录]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/130673284</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/130673284</guid><author>u011925590</author><pubDate>Sun, 14 May 2023 20:48:00 +0800</pubDate><description><![CDATA[单张表查询各科成绩前两名的记录]]></description><category></category></item><item><title><![CDATA[left join关联查询一对多数据重复问题解决方案]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/128675854</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/128675854</guid><author>u011925590</author><pubDate>Fri, 13 Jan 2023 16:29:34 +0800</pubDate><description><![CDATA[关联查询一对多问题，GROUP_CONCAT]]></description><category></category></item><item><title><![CDATA[excel函数记录]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/128394068</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/128394068</guid><author>u011925590</author><pubDate>Wed, 21 Dec 2022 10:51:08 +0800</pubDate><description><![CDATA[Excel 函数文本连接  TEXTJOIN]]></description><category></category></item><item><title><![CDATA[mysql 一对多查询 合并为一行数据]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/128004917</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/128004917</guid><author>u011925590</author><pubDate>Wed, 23 Nov 2022 18:04:08 +0800</pubDate><description><![CDATA[mysql 一对多查询 合并为一行数据]]></description><category></category></item><item><title><![CDATA[用array_filter清除数组中的空值]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/127998799</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/127998799</guid><author>u011925590</author><pubDate>Wed, 23 Nov 2022 14:21:40 +0800</pubDate><description><![CDATA[用array_filter清除数组中的空值]]></description><category></category></item><item><title><![CDATA[git blame 追溯指定文件的历史修改记录]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/126831615</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/126831615</guid><author>u011925590</author><pubDate>Tue, 13 Sep 2022 13:25:58 +0800</pubDate><description><![CDATA[git blame 追溯指定文件的历史修改记录]]></description><category></category></item><item><title><![CDATA[Yii post()追加数据,模块之间的调用runAction]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/125908453</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/125908453</guid><author>u011925590</author><pubDate>Thu, 21 Jul 2022 11:25:28 +0800</pubDate><description><![CDATA[Yii]]></description><category></category></item><item><title><![CDATA[打印sql]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/125805681</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/125805681</guid><author>u011925590</author><pubDate>Fri, 15 Jul 2022 15:31:07 +0800</pubDate><description><![CDATA[sql打印]]></description><category></category></item><item><title><![CDATA[添加管理员账号]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/125059512</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/125059512</guid><author>u011925590</author><pubDate>Tue, 31 May 2022 10:08:20 +0800</pubDate><description><![CDATA[1、新建用户，这里新建一个temp_test的用户

adduser temp_test

2、设置新用户密码

passwd temp_test

3、将sudoers文件的权限修改成可编辑

chmod -v u+w /etc/sudoers

4、使用vim编辑sudoers文件

vim /etc/sudoers

5、在sudoes文件中添加如下的内容

找到root    ALL=(ALL)      ALL

然后添加temp_user   ALL=(ALL)   ...]]></description><category></category></item><item><title><![CDATA[PHP中array_unique()函数产生的Array to String conversation警告]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/123246787</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/123246787</guid><author>u011925590</author><pubDate>Thu, 03 Mar 2022 10:05:02 +0800</pubDate><description><![CDATA[array_unique()
函数原型为

array_unique ( array $array , int $sort_flags = SORT_STRING ) : array
1
注意到：可选参数sort_flags的默认值为SORT_STRING，意为将数组中的元素按照字符串进行排序。
所以此处有一个字符串转换，但数组中的元素仍为数组（即多维数组）时，若不改变sort_flags参数则会造成Array to String conversation错误。
将sort_flags参数修改为SORT_.]]></description><category></category></item><item><title><![CDATA[redis查看使用的是哪个配置文件]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/122825886</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/122825886</guid><author>u011925590</author><pubDate>Tue, 08 Feb 2022 16:04:57 +0800</pubDate><description><![CDATA[redis-cli 进入客户端

info server 查看配置信息




]]></description><category></category></item><item><title><![CDATA[CentOS修改SSH端口号]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/122364959</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/122364959</guid><author>u011925590</author><pubDate>Fri, 07 Jan 2022 15:09:55 +0800</pubDate><description><![CDATA[1、在#Port 22行去掉#号注释，同时加入想要使用的端口号如 Port 22438
vim /etc/ssh/sshd_config
这里保留22端口是为了防止当前无法使用ssh登录

2、修改防火墙配置
firewall-cmd --zone=public --add-port=22438/tcp --permanent
成功返回success
重启防火墙：
firewall-cmd --reload
成功返回success
查看添加端口是否成功，成功则显示yes，否则为no：
firewall-cm]]></description><category></category></item><item><title><![CDATA[CentOS添加管理员账号]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/122364900</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/122364900</guid><author>u011925590</author><pubDate>Fri, 07 Jan 2022 15:08:52 +0800</pubDate><description><![CDATA[1、新建用户，这里新建一个temp_test的用户

adduser temp_test

2、设置新用户密码

passwd temp_test

3、将sudoers文件的权限修改成可编辑

chmod -v u+w /etc/sudoers

4、使用vim编辑sudoers文件

vim /etc/sudoers

5、在sudoes文件中添加如下的内容

找到root    ALL=(ALL)      ALL

然后添加temp_user   ALL=(ALL)   ...]]></description><category></category></item><item><title><![CDATA[mysql常用函数]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/121655520</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/121655520</guid><author>u011925590</author><pubDate>Wed, 01 Dec 2021 15:01:03 +0800</pubDate><description><![CDATA[1、SQL查询某一字段重复的数据
select * from 数据表 WHERE重复记录字段 in (select 重复记录字段 from 数据表 group by 重复记录字段 having count(重复记录字段)&gt;1)
]]></description><category></category></item><item><title><![CDATA[Yii2 获取当前请求的路由信息]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/121616298</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/121616298</guid><author>u011925590</author><pubDate>Mon, 29 Nov 2021 18:26:39 +0800</pubDate><description><![CDATA[Yii::$app-&gt;controller-&gt;route;
Yii::$app-&gt;requestedRoute；


]]></description><category></category></item><item><title><![CDATA[empty调用数组中不存在的键名与 空数组循环问题]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/121423228</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/121423228</guid><author>u011925590</author><pubDate>Fri, 19 Nov 2021 15:12:01 +0800</pubDate><description><![CDATA[1、设置一个数组empty()函数调用数组中不存在的键时，返回值为true

2、循环空数组，循环中的代码不执行


]]></description><category></category></item><item><title><![CDATA[PHP递归函数return返回null的问题]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/119416098</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/119416098</guid><author>u011925590</author><pubDate>Thu, 05 Aug 2021 13:44:20 +0800</pubDate><description><![CDATA[public function getNumber($number,$num='1'){
    //后面三位流水改成按照顺序生成
    $num=str_pad($num,3,"0",STR_PAD_LEFT);
    $instrument_number = $number. $num;
    //查询是否被占用
    $meterInfo = Meter::find()-&gt;where(['is_delete' =&gt; 0,'instrument_number' =&gt; $ins.]]></description><category></category></item><item><title><![CDATA[文章记录地址]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/115327236</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/115327236</guid><author>u011925590</author><pubDate>Tue, 30 Mar 2021 15:35:43 +0800</pubDate><description><![CDATA[Laravel 服务容器、服务提供器、契约实例讲解  https://learnku.com/articles/17638#0695ff
]]></description><category></category></item><item><title><![CDATA[简单实现获取上午下午晚上状态类]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/115297590</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/115297590</guid><author>u011925590</author><pubDate>Mon, 29 Mar 2021 11:42:48 +0800</pubDate><description><![CDATA[&lt;?php
  class MyGreeter{

  public static $instance = null;


  public function __construct()
  {
    $this-&gt;getGreeting();
  }

 public static function getInstance()
  {
    if (is_null(self::$instance)) {
      self::$i...]]></description><category></category></item><item><title><![CDATA[字符串、数字、布尔值比较]]></title><link>https://blog.youkuaiyun.com/u011925590/article/details/115178505</link><guid>https://blog.youkuaiyun.com/u011925590/article/details/115178505</guid><author>u011925590</author><pubDate>Wed, 24 Mar 2021 15:38:03 +0800</pubDate><description><![CDATA[字符串和数字比较，字符串转数字 

var_dump('{'==0); //true

var_dump('{'==1);//false

数字和布尔型比较转布尔型

var_dump(true==0); //false

var_dump(false==0); //true

字符串和布尔型比较 转布尔型

var_dump('{'==true); //true

var_dump(''==true); //false
...]]></description><category></category></item></channel></rss>