国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Table of Contents
Reply content:
Home Backend Development PHP Tutorial How to query the hierarchical information of the classification directory as efficiently as possible?

How to query the hierarchical information of the classification directory as efficiently as possible?

Jul 06, 2016 pm 01:52 PM
memcached mysql nosql php redis

I have a simple article classification table, the main structure is as follows

id 父id 標題
1 0 所有項目
2 1 PHP
3 1 Mysql
4 2 ThinkPHP

...
etc. It should be a very common directory structure.
means that 所有項目 is the first level, PHP and Mysql are the second level, and ThinkPHP is the third level directory of PHP.

Then the question is, assuming I only know the data id=4, how can I list the breadcrumb navigation such as
所有項目 >> PHP >> ThinkPHP
?

Of course I know that I can list it using a loop, but it always feels like a waste of performance. Is there a faster way?
No answers to similar questions were found. Maybe I didn’t use the keywords reasonably enough. Finally I have no choice but to ask a question, thank you in advance for your generous advice

Reply content:

I have a simple article classification table, the main structure is as follows

id 父id 標題
1 0 所有項目
2 1 PHP
3 1 Mysql
4 2 ThinkPHP

...
etc. It should be a very common directory structure.
means that 所有項目 is the first level, PHP and Mysql are the second level, and ThinkPHP is the third level directory of PHP.

Then the question is, assuming I only know the data id=4, how can I list the breadcrumb navigation such as
所有項目 >> PHP >> ThinkPHP
?

Of course I know that I can list it using a loop, but it always feels like a waste of performance. Is there a faster way?
No answers to similar questions were found. Maybe I didn’t use the keywords reasonably enough. Finally I have no choice but to ask a question, thank you in advance for your generous advice

Add another field to find all parent categories and generate breadcrumbs when adding a new subcategory. Of course, the data stored in this field can be stored flexibly, and fixed breadcrumbs do not have to be generated. You can generate an array, josn or serialize it and save it, and then take it out to generate breadcrumbs in real time to cope with the flexible generation and change of breadcrumbs.

The most important idea is to store the parent class data when adding a new subclass, which is similar to the principle of static caching.

There is no other way, because since you need to use breadcrumbs (from 4 to 2 to 1), you must have a query and extraction process.

It’s just a matter of recursion or iteration

If your category has a fixed number of levels, you can write a specified SQL for each level to reduce the number of requests. Loop queries at the code level waste performance, but the code implementation is simple and highly flexible

First of all, you can determine the hierarchical directory data of a website, which will not be very much.
You can completely take out all the data from the db.
Then recursively traverse.
The consumption Time operations are placed at the code level to reduce database queries.

There are not many efficient methods, cache should be one

Thanks for the invitation. Generally, the changes to this kind of classification are very small. You can use foreach to traverse it and cache it for later use. This is how I usually use it

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

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

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

PHP Tutorial
1502
276
Object-Relational Mapping (ORM) Performance Tuning in PHP Object-Relational Mapping (ORM) Performance Tuning in PHP Jul 29, 2025 am 05:00 AM

Avoid N 1 query problems, reduce the number of database queries by loading associated data in advance; 2. Select only the required fields to avoid loading complete entities to save memory and bandwidth; 3. Use cache strategies reasonably, such as Doctrine's secondary cache or Redis cache high-frequency query results; 4. Optimize the entity life cycle and call clear() regularly to free up memory to prevent memory overflow; 5. Ensure that the database index exists and analyze the generated SQL statements to avoid inefficient queries; 6. Disable automatic change tracking in scenarios where changes are not required, and use arrays or lightweight modes to improve performance. Correct use of ORM requires combining SQL monitoring, caching, batch processing and appropriate optimization to ensure application performance while maintaining development efficiency.

VSCode settings.json location VSCode settings.json location Aug 01, 2025 am 06:12 AM

The settings.json file is located in the user-level or workspace-level path and is used to customize VSCode settings. 1. User-level path: Windows is C:\Users\\AppData\Roaming\Code\User\settings.json, macOS is /Users//Library/ApplicationSupport/Code/User/settings.json, Linux is /home//.config/Code/User/settings.json; 2. Workspace-level path: .vscode/settings in the project root directory

A Deep Dive into PHP's Internal Garbage Collection Mechanism A Deep Dive into PHP's Internal Garbage Collection Mechanism Jul 28, 2025 am 04:44 AM

PHP's garbage collection mechanism is based on reference counting, but circular references need to be processed by a periodic circular garbage collector; 1. Reference count releases memory immediately when there is no reference to the variable; 2. Reference reference causes memory to be unable to be automatically released, and it depends on GC to detect and clean it; 3. GC is triggered when the "possible root" zval reaches the threshold or manually calls gc_collect_cycles(); 4. Long-term running PHP applications should monitor gc_status() and call gc_collect_cycles() in time to avoid memory leakage; 5. Best practices include avoiding circular references, using gc_disable() to optimize performance key areas, and dereference objects through the ORM's clear() method.

The Serverless Revolution: Deploying Scalable PHP Applications with Bref The Serverless Revolution: Deploying Scalable PHP Applications with Bref Jul 28, 2025 am 04:39 AM

Bref enables PHP developers to build scalable, cost-effective applications without managing servers. 1.Bref brings PHP to AWSLambda by providing an optimized PHP runtime layer, supports PHP8.3 and other versions, and seamlessly integrates with frameworks such as Laravel and Symfony; 2. The deployment steps include: installing Bref using Composer, configuring serverless.yml to define functions and events, such as HTTP endpoints and Artisan commands; 3. Execute serverlessdeploy command to complete the deployment, automatically configure APIGateway and generate access URLs; 4. For Lambda restrictions, Bref provides solutions.

Building Immutable Objects in PHP with Readonly Properties Building Immutable Objects in PHP with Readonly Properties Jul 30, 2025 am 05:40 AM

ReadonlypropertiesinPHP8.2canonlybeassignedonceintheconstructororatdeclarationandcannotbemodifiedafterward,enforcingimmutabilityatthelanguagelevel.2.Toachievedeepimmutability,wrapmutabletypeslikearraysinArrayObjectorusecustomimmutablecollectionssucha

Integrating PHP with Machine Learning Models Integrating PHP with Machine Learning Models Jul 28, 2025 am 04:37 AM

UseaRESTAPItobridgePHPandMLmodelsbyrunningthemodelinPythonviaFlaskorFastAPIandcallingitfromPHPusingcURLorGuzzle.2.RunPythonscriptsdirectlyfromPHPusingexec()orshell_exec()forsimple,low-trafficusecases,thoughthisapproachhassecurityandperformancelimitat

css dark mode toggle example css dark mode toggle example Jul 30, 2025 am 05:28 AM

First, use JavaScript to obtain the user system preferences and locally stored theme settings, and initialize the page theme; 1. The HTML structure contains a button to trigger topic switching; 2. CSS uses: root to define bright theme variables, .dark-mode class defines dark theme variables, and applies these variables through var(); 3. JavaScript detects prefers-color-scheme and reads localStorage to determine the initial theme; 4. Switch the dark-mode class on the html element when clicking the button, and saves the current state to localStorage; 5. All color changes are accompanied by 0.3 seconds transition animation to enhance the user

Java Performance Optimization and Profiling Techniques Java Performance Optimization and Profiling Techniques Jul 31, 2025 am 03:58 AM

Use performance analysis tools to locate bottlenecks, use VisualVM or JProfiler in the development and testing stage, and give priority to Async-Profiler in the production environment; 2. Reduce object creation, reuse objects, use StringBuilder to replace string splicing, and select appropriate GC strategies; 3. Optimize collection usage, select and preset initial capacity according to the scene; 4. Optimize concurrency, use concurrent collections, reduce lock granularity, and set thread pool reasonably; 5. Tune JVM parameters, set reasonable heap size and low-latency garbage collector and enable GC logs; 6. Avoid reflection at the code level, replace wrapper classes with basic types, delay initialization, and use final and static; 7. Continuous performance testing and monitoring, combined with JMH

See all articles