刚刚在phpmyadmin 添加了几个索引,现在删除不了了,咋办?
用了“ALTER TABLE `mayi_record` DROP INDEX ( `adddate` , `adddate1` , `adddate2` );”语句
提示:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '( `adddate` , `adddate1` , `adddate2` )' at line 1
回复讨论(解决方案)
你看你的图,最左下角还有个 +索引,点一下就别有洞天了!
你看你的图,最左下角还有个 +索引,点一下就别有洞天了!
哈哈,我终于找到宝藏了。。。
ALTER TABLE `mayi_record` DROP INDEX indexname ( `adddate` , `adddate1` , `adddate2` );
ALTER TABLE `mayi_record` DROP INDEX indexname ( `adddate` , `adddate1` , `adddate2` );
谢谢,最近在看学习索引。非常感谢。

There are three ways to implement hot updates for functions in PHP: 1. Rewrite the function and use runkit to dynamically rewrite the function; 2. Use OPcache to realize hot updates by restarting OPcache; 3. Use external tools such as deployer or ansible to automatically deploy and update code.

In PHP, you can use the following methods to traverse and replace array elements: 1. Use a foreach loop and reference (&$value) to modify the elements, but be aware that references may cause side effects. 2. Use a for loop to directly access indexes and values to avoid reference problems. 3. Use the array_map function to make concise modifications, but the key name will be reset. 4. Use the array_walk function to modify the value and retain the key name. Performance, side effects and key name retention requirements should be taken into account when selecting a method.

Verifying ISBN strings in PHP can be implemented through a function that can handle two formats: ISBN-10 and ISBN-13. 1. Remove all non-numeric characters. 2. For ISBN-10, weighted sum calculation is used, and it is valid if the result can be divided by 11. 3. For ISBN-13, different weighting sum calculations are used, and it is valid if the result can be divided by 10. This function returns a Boolean value indicating whether the ISBN is valid.

In PHP, automatically loading classes are implemented through the __autoload or spl_autoload_register function. 1. The __autoload function has been abandoned, 2. The spl_autoload_register function is more flexible, supports multiple automatic loading functions, and can handle namespace and performance optimization.

Methods to modify array elements in PHP include direct assignment and batch modification using functions. 1. For indexed arrays, such as $colors=['red','green','blue'], the second element can be modified by $colors[1]='yellow'. 2. For associative arrays, such as $person=['name'=>'John','age'=>30], the value of age can be modified by $person['age']=31. 3. Use array_map or array_walk functions to modify array elements in batches, such as $numbers=array_map(fun

Implementing hook functions in PHP can be implemented through observer mode or event-driven programming. The specific steps are as follows: 1. Create a HookManager class to register and trigger hooks. 2. Use the registerHook method to register the hook and trigger the hook by the triggerHook method when needed. Hook functions can improve the scalability and flexibility of the code, but pay attention to performance overhead and debugging complexity.

ThesecrettokeepingaPHP-poweredwebsiterunningsmoothlyunderheavyloadinvolvesseveralkeystrategies:1)ImplementopcodecachingwithOPcachetoreducescriptexecutiontime,2)UsedatabasequerycachingwithRedistolessendatabaseload,3)LeverageCDNslikeCloudflareforservin

You should care about DependencyInjection(DI) because it makes your code clearer and easier to maintain. 1) DI makes it more modular by decoupling classes, 2) improves the convenience of testing and code flexibility, 3) Use DI containers to manage complex dependencies, but pay attention to performance impact and circular dependencies, 4) The best practice is to rely on abstract interfaces to achieve loose coupling.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

Atom editor mac version download
The most popular open source editor

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
