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怎么解决MQTT连接掉线，自动连接问题，同时解决，反复断开连接，断开连接问...
解决MQTT退出后台后掉线自动连接问题，现在可以实现自动连接，但是在返回控制界面的时候，反复断开反复链接，还有切换页面的时候返回也是同样的问题，还有连接一个服务器，需要每个页面单独设置MQTT连接吗，是不是可以...
How to enable mod_rewrite for Apache 2.2
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In order to use mod_rewrite you can type the following command in the terminal:
sudo a2enmod rewrite
Restart apache2 after
sudo /etc/init.d/apache2 restart
or
sudo service apache2 restart
or as per new unified System Co...
How can I create an array with key value pairs?
...irs to the end of the array, even if you have integer keys. PHP arrays are ordered, so if you want to prepend an array with a key-value pair, you have to do this: $data = ['user_email' => joy@cargomar.org'] + $data.
– totymedli
May 9 '18 at 22:31
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TCP 的那些事儿（上） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...些事儿（上）TCP是一个巨复杂的协议，因为他要解决很多问题，而这些问题又带出了很多子问题和阴暗面。所以学习TCP本身是个比较痛苦的过程，但对于学习的...
TCP是一个巨复杂的协议，因为他要解决很多问题，而这些问题又...
淘宝网采用什么技术架构来实现网站高负载的 - 更多技术 - 清泛网 - 专注C/C...
...，我们怎么办?通常来说，我们都是通过集群来解决这个问题，而通常所说的集群，不仅有负载均衡，更重要的是要有失效恢复failover,比如tomcat采 用的集群节点广播复制，jboss采 用的配对复制等session状 态复制策略，但是集群中...
PHP CURL DELETE request
I'm trying to do a DELETE http request using PHP and cURL.
5 Answers
5
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VIM Disable Automatic Newline At End Of File
So I work in a PHP shop, and we all use different editors, and we all have to work on windows. I use vim, and everyone in the shop keeps complaining that whenever I edit a file there is a newline at the bottom. I've searched around and found that this is a documented behavior of vi & vim... but I w...
Best way to select random rows PostgreSQL
... select * from table where random() < 0.01;
EXPLAIN select * from table order by random() limit 1000;
A quick test on a large table1 shows, that the ORDER BY first sorts the complete table and then picks the first 1000 items. Sorting a large table not only reads that table but also involves rea...
How can I return pivot table output in MySQL?
...NT x pages) resemble conditions. The main grouping is by company_name.
In order to set up the conditions this rather shouts for using the CASE-statement. In order to group by something, well, use ... GROUP BY.
The basic SQL providing this pivot can look something like this:
SELECT P.`company_nam...
php 获取操作系统、浏览器版本信息（持续更新） - 更多技术 - 清泛网 - 专...
php 获取操作系统、浏览器版本信息（持续更新）有时我们需要在服务器端收集用户操作系统版本，以及用户使用何种浏览器等信息，本文主要提供getOS、getBrowser、getBrowserVer三个方法，对网上各方法进行测试汇总整理，持续更新...