Most developers can write queries… but don’t understand how they actually work 👇 SELECT ≠ GROUP BY SELECT → fetch data from a table 📄 GROUP BY → organize data into meaningful groups for aggregation When building real systems, you don’t just use SELECT — you rely on GROUP BY with aggregation (COUNT, SUM, AVG) to handle analytics, reporting, and scaling data insights. For example, finding total users is easy… but finding users per country, revenue per month, or active users per feature — that’s where GROUP BY comes in This small distinction changes how you design systems. Building systems > memorizing concepts 🚀 What’s one concept developers often misunderstand? 🤔 #fullstackdeveloper #softwareengineering #webdevelopment #javascript #reactjs #backend #buildinpublic
Adarsh Singh’s Post
More Relevant Posts
-
𝐌𝐚𝐬𝐭𝐞𝐫𝐢𝐧𝐠 𝐒𝐭𝐚𝐭𝐞 𝐋𝐨𝐠𝐢𝐜 & 𝐂𝐑𝐔𝐃 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐨𝐧𝐬 ⚛️ Yesterday was about the "comeback," but today is about the "consistency." I spent my session diving into dynamic data management—building a Name Manager that handles full CRUD (Create, Read, Update, Delete) logic. To move from static pages to interactive apps, I focused on these three technical pillars: 🔹 𝐮𝐬𝐞𝐒𝐭𝐚𝐭𝐞 (𝐓𝐡𝐞 𝐌𝐞𝐦𝐨𝐫𝐲): In React, components reset on every render. useState acts as the persistent "brain," allowing the app to remember data even when the UI updates. I practiced using setter functions to trigger re-renders safely. 🔹 .𝐦𝐚𝐩() (𝐓𝐡𝐞 𝐔𝐈 𝐅𝐚𝐜𝐭𝐨𝐫𝐲): This is how we turn raw data into an interface. It loops through an array and transforms strings into interactive components. It’s the engine behind every dynamic list you see online. 🔹 .𝐟𝐢𝐥𝐭𝐞𝐫() (𝐓𝐡𝐞 𝐈𝐦𝐦𝐮𝐭𝐚𝐛𝐥𝐞 𝐃𝐞𝐥𝐞𝐭𝐞): React rule #1: Don't mutate state. Instead of "erasing" data from the original array, I used .filter() to create a brand-new copy. This is the secret to building predictable, bug-free applications. 𝐖𝐡𝐚𝐭 𝐈 𝐢𝐦𝐩𝐥𝐞𝐦𝐞𝐧𝐭𝐞𝐝 𝐭𝐨𝐝𝐚𝐲: ✅ Create: Added new entries using the Spread Operator [...]. ✅ Read: Rendered a dynamic, real-time list with .map(). ✅ Update/Delete: Built the logic to modify and remove specific items without breaking the state. 𝐓𝐡𝐞 𝐁𝐢𝐠 𝐓𝐚𝐤𝐞𝐚𝐰𝐚𝐲: In React, we don't modify the past; we create a fresh copy of the future! 🚀 #ReactJS #WebDevelopment #JavaScript #FrontendDeveloper #LearningInPublic
To view or add a comment, sign in
-
Stop over-complicating data fetching in React. Seriously. If you're still juggling useEffect + useState for async logic… you're writing 2020 code in 2026. ❌ The Problem The “old way” looks simple. Until it isn’t. Duplicate loading states everywhere Manual error handling Race conditions you didn’t expect Context usage becomes deeply nested Code becomes harder to reason about What started as “just fetch data” turns into a mess. ✅ The Solution: use() Hook React introduced something radically simpler. use() lets you read async data directly. No extra state. No effect boilerplate. What makes it powerful: Works with Promises → const data = use(fetchData()) Works with Context → const theme = use(ThemeContext) Supports conditional usage → Yes, you can call it inside conditions Built for Suspense → Loading states handled automatically ⚡ Why this is a big deal This isn’t just a new hook. It changes how React apps are structured. Less client-side complexity More server-driven rendering Cleaner, synchronous-looking code 🎯 Why this matters for your next interview Interviewers are shifting focus. They don’t care if you can write useEffect. Everyone can. They care if you understand: Server Components architecture How Suspense handles async UI Why React is moving away from imperative data fetching When use() is better than traditional hooks If you explain this well… you instantly stand out. 💭 Final Thought React is moving toward simplicity. But only if you evolve with it. Are you switching to use()… or still holding onto useEffect? 👇 #ReactJS #WebDev #JavaScript #FrontendDevelopment #ReactDeveloper #SoftwareEngineering #CodingLife #TechCareers #Programming #FullStackDevelopment #FrontendEngineer #100DaysOfCode #LearnToCode #DeveloperCommunity
To view or add a comment, sign in
-
-
I built a real User Management System from scratch Most developers start with tutorials… I decided to turn knowledge into a real working project. I just built a fully functional User Management Dashboard using vanilla JavaScript. 🔹 What it does: ✔ Fetches real user data from an API ✔ Lets you add new users dynamically ✔ Search users in real time ✔ Delete users instantly ✔ Stores data using Local Storage 🔹 Tech Stack: HTML • CSS • JavaScript • API Integration What I learned from this project is not just coding… but how real systems handle data, interaction, and user experience. 💡 Still improving, still building… one project at a time. 🔗 GitHub: https://lnkd.in/dJZjgYsp I’d appreciate any feedback or suggestions 🙌 #WebDevelopment #Frontend #JavaScript #CodingJourney #BuildInPublic
To view or add a comment, sign in
-
-
You’re still building forms manually from JSON? --- Every time I get a JSON response, I end up doing the same thing: → read structure → map fields → wire inputs → repeat… again --- It’s boring. It’s repetitive. And it shouldn’t exist in 2026. --- So I built something for myself: 👉 Paste JSON 👉 Get a working form instantly --- No setup. No backend. No config headaches. Just: JSON → UI --- Introducing: 🔧 JSON → Form (part of useSignal) 👉 https://lnkd.in/grSx-SEi --- It’s fully browser-native. Which means: - your data never leaves your machine - everything runs instantly - no dependency on any service --- This isn’t just a generator. It’s a way to: → skip repetitive UI work → prototype faster → actually focus on logic --- Try it once. You probably won’t go back to building forms manually. --- 💬 Curious — how are you handling JSON → forms today? #frontend #webdevelopment #javascript #reactjs #devtools #buildinpublic #productivity #developers #webdev
To view or add a comment, sign in
-
-
In this post, I focused on visualizing how data moves within a React application using a Data Flow Diagram (DFD). Understanding data flow allows developers to: • Build more organized and scalable applications • Avoid unnecessary complexity and bugs • Clearly separate logic from UI • Improve maintainability and readability This approach helped me move beyond writing components to truly understanding how data drives the entire application. #React #Frontend #WebDevelopment #JavaScript #SoftwareArchitecture #CleanCode
To view or add a comment, sign in
-
-
I used to fetch data only in the browser… Today I realized I don’t always need to. Day 8 of my 30-day Next.js deep dive. For the last few days, I explored fetching data in Server Components. At first, it felt unfamiliar because I’ve always used useEffect and client-side fetching in React. But this approach in Next.js changes how data flows in an application. Key Learnings - Server Components allow fetching data directly on the server - No need for useEffect or extra client-side state for initial data - Reduces JavaScript sent to the browser → better performance - Keeps sensitive logic (like API calls) on the server - Makes the initial page load faster and more efficient My confusion started when I tried using hooks like useState while fetching data—and it didn’t work. That’s when I understood: 👉 Server Components are not interactive by default 👉 They are meant for data fetching and rendering, not interactivity This changed my mindset from: “Fetch everything in the client.” to “Fetch data where it makes the most sense.” I’m learning to think more about performance and architecture—not just making things work. Because in real-world applications (especially remote teams), efficient data handling is a big deal. Do you prefer fetching data on the server or client in your projects and why? #NextJS #ReactJS #WebDevelopment #FullStackDeveloper #JavaScript #Performance #LearningInPublic #RemoteDeveloper
To view or add a comment, sign in
-
-
For the longest time, my pattern looked like this: • useEffect → call API • useState → store data • loading + error states manually handled It worked… until the app grew. Then came the problems: • duplicate API calls • inconsistent loading states • manual caching (or no caching at all) • refetching logic scattered everywhere That’s when I switched to React Query. — What changed? Server state ≠ UI state React Query made this distinction clear. Caching became automatic Data stays fresh without unnecessary refetching. Background updates UI stays responsive while data syncs silently. Built-in loading & error handling No more boilerplate in every component. Refetching is declarative Not tied to lifecycle hacks anymore. — The biggest mindset shift: Stop thinking: “Where should I fetch this data?” Start thinking: “How should this data behave over time?” — Final takeaway: React Query is not just a library. It’s a different way of thinking about data in frontend. And once you get it, going back to useEffect feels… painful 😅 #reactjs #frontend #javascript #webdevelopment #reactquery #softwareengineering
To view or add a comment, sign in
-
🤯 Ever hit “Update”… and your UI still shows OLD data? I thought my API was broken. User clicks: 👉 Update Profile API responds: 👉 Success ✅ But the UI? 👉 Still showing old values 😬 I refreshed the page… 👉 Now it’s correct. So what actually happened? ⚠️ It wasn’t the backend issue. It was frontend state issue. Here’s the truth most devs learn the hard way: Updating data ≠ Updating UI Common culprits: 👉 State not updated correctly 👉 Cached data still hanging around 👉 Async updates causing lag 💥 Result: Your backend is right… …but your UI is lying. 💡 The Fix? : ✔️ Update state instantly (Optimistic UI) ✔️ Refetch after mutation ✔️ Invalidate cache properly (RTK Query / React Query) 🔥 After fixing: ✔️ UI updates instantly ✔️ Users trust the system ✔️ App feels FAST & reliable 🧠 Real lesson: A perfect API means nothing if your UI tells a different story. 💬 Tell me... Have you ever debugged this “ghost data” bug? #frontend #reactjs #webdevelopment #javascript #stateManagement #rtkquery #reactquery #softwareengineering #programming #developers
To view or add a comment, sign in
-
-
𝐈𝐬 𝐲𝐨𝐮𝐫 `𝐮𝐬𝐞𝐄𝐟𝐟𝐞𝐜𝐭` 𝐟𝐢𝐫𝐢𝐧𝐠 𝐰𝐚𝐲 𝐭𝐨𝐨 𝐨𝐟𝐭𝐞𝐧? 𝐘𝐨𝐮 𝐦𝐢𝐠𝐡𝐭 𝐛𝐞 𝐟𝐚𝐥𝐥𝐢𝐧𝐠 𝐟𝐨𝐫 𝐚 𝐜𝐨𝐦𝐦𝐨𝐧 𝐝𝐞𝐩𝐞𝐧𝐝𝐞𝐧𝐜𝐲 𝐚𝐫𝐫𝐚𝐲 𝐭𝐫𝐚𝐩. We've all been there: you put an object or array into your `useEffect`'s dependency array, thinking it's stable. But because JavaScript compares objects and arrays by reference, even if their content is identical, `useEffect` sees a new object on every render and re-runs your effect. This can lead to performance hits, stale data, or even infinite loops. 🚫 The Problem: ```javascript function MyComponent({ data }) { const options = { id: data.id, filter: 'active' }; useEffect(() => { // This runs every render if 'options' object is new fetchData(options); }, [options]); // 'options' is a new object reference each time // ... } ``` ✅ The Fix: Stabilize with `useMemo` If your object or array doesn't logically change across renders (or only changes based on specific primitives), wrap it in `useMemo`. This memoizes the object itself, ensuring its reference remains the same unless its dependencies actually change. ```javascript function MyComponent({ data }) { const stableOptions = useMemo(() => ({ id: data.id, filter: 'active' }), [data.id]); // Only re-create if data.id changes useEffect(() => { fetchData(stableOptions); }, [stableOptions]); // Now only re-runs if stableOptions' reference changes // ... } ``` This trick is a lifesaver for optimizing `useEffect` calls, especially when dealing with complex configurations or filtering logic passed down as props. It keeps your effects clean and your app performant. What's been your biggest `useEffect` headache, and how did you solve it? #React #FrontendDevelopment #JavaScript #Performance #WebDev
To view or add a comment, sign in
Explore content categories
- Career
- Productivity
- Finance
- Soft Skills & Emotional Intelligence
- Project Management
- Education
- Technology
- Leadership
- Ecommerce
- User Experience
- Recruitment & HR
- Customer Experience
- Real Estate
- Marketing
- Sales
- Retail & Merchandising
- Science
- Supply Chain Management
- Future Of Work
- Consulting
- Writing
- Economics
- Artificial Intelligence
- Employee Experience
- Workplace Trends
- Fundraising
- Networking
- Corporate Social Responsibility
- Negotiation
- Communication
- Engineering
- Hospitality & Tourism
- Business Strategy
- Change Management
- Organizational Culture
- Design
- Innovation
- Event Planning
- Training & Development