| 私有ip地址 | 子网掩码 |
|---|---|
| 10.0.0.0 - 10.255.255.255 | 255.0.0.0 |
| 172.16.0.0 - 172.31.255.255 | 255.255.0.0 |
| 192.168.0.0 - 192.168.0.255 | 255.255.255.0 |
| 常用网段 | 掩码 |
|---|---|
| 192.168.1.0 | 255.255.255.0 |
常用网关：192.168.1.1 或 192.168.1.254
| 特殊IP地址 | 用途 |
|---|---|
| 0.0.0.0 | 任意地址 |
| 255.255.255.255 | 有限广播地址 |
| 127.0.0.1 | 环回地址 |
| 169.254.X.X | APIPA地址（本地链路地址） |
| 1.2.4.8 | CNNIC SDNS |
| 8.8.8.8 | 谷歌DNS地址 |
| 223.5.5.5 | 阿里云公共DNS |
| 223.6.6.6 | 阿里云公共DNS |
| 114.114.114.114 | 114公共DNS |
| 119.29.29.29 | 腾讯公共DNS |
| 180.76.76.76 | 百度公共DNS |
修改.htaccess文件：
<IfModule mod_rewrite.c>
Options +FollowSymlinks -Multiviews
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ router.php?/$1 [QSA,PT,L]
SetEnvIf Authorization "(.*)" HTTP_AUTHORIZATION=$1
</IfModule>select concat('update ck_auth_rule set weigh = ',rn,' where id = ',id,';') as sql_text
from (select id,pid,
100 - row_number() over(partition by pid order by id) as rn
from ck_auth_rule ) t ;日期 between ''的时候报错1525 - Incorrect DATE value: ''日期 between NULLIF('','')NULLIF(p1,p2)p1 = p2，值为NULL，否则，值为p1SELECT *
FROM information_schema.ROUTINES
WHERE ROUTINE_SCHEMA = DATABASE();