Building SQL Foundation with Subqueries and Joins

Today’s SQL Learning: Functions + Wrapping Queries I spent time understanding SQL Functions deeply — not just writing them, but actually knowing where and how to use them in real queries Here’s what I explored 👇 🔹 Learned how to create reusable functions 🔹 Used functions inside different clauses: ✔ SELECT → for calculated columns ✔ WHERE → for filtering ✔ ORDER BY → for sorting ✔ GROUP BY & HAVING → for grouping & filtering data ✔ CASE → for adding logic But the most important realization today was 👇 ❌ Functions have limitations * Cannot return multiple rows * Cannot directly use INSERT / UPDATE inside them * Cannot behave like full queries 👉 That means we can’t wrap every query inside a function 👉 We must convert logic into single-value outputs 🔥 Today I feel: * More confident with SQL functions * Better understanding of when to use functions vs queries * More comfortable writing clean, reusable logic #SQL #DataAnalytics #LearningJourney #Functions #SQLPractice #Growth

Mastering SQL isn’t about writing queries… it’s about solving complex problems efficiently. From window functions to CTEs, indexing to performance tuning — Advanced SQL transforms raw data into real insights 🚀 If you’re still using just basic SELECT statements, you’re only scratching the surface. #SQL #DataAnalytics #DataEngineering #Learning #TechSkills

🚀 Day 32 of My SQL Learning Journey Today I practiced a SQL problem based on JOIN operations 🔹 Problem: Retrieve product name, year, and price for each sale 🔗 Problem Link: https://lnkd.in/gBgY3zhW 🔹 Key Learning: Using JOIN to combine multiple tables Retrieving meaningful data from relational databases Importance of foreign key relationships 💡 JOINs are one of the most important concepts in SQL! Consistency continues 🚀 #SQL #LeetCode #90DaysOfCode #DataAnalytics #CodingJourney

Day 27 of my SQL Night Learning Journey 🌙 Today, I learned about the SELECT INTO statement, and it made things feel a lot more practical. In simple terms, SELECT INTO helps you create a new table from an existing one while copying the data into it at the same time. Think of it like: “Take this table, duplicate it, and save it as a new one.” This is especially useful when: You want to create a backup of your data You need a temporary table to run the analysis without touching the original data One important thing I learned: The new table copies the columns and data types, but it does NOT automatically include things like: Primary keys Indexes NOT NULL constraints So it’s not a perfect clone, but it gets the job done for most use cases. A simple example that stood out to me: Creating a backup of a table by copying everything into a new one. Little by little, SQL is starting to feel less intimidating and more like a tool I can actually use 🛠️ #SQL #LearningInPublic #DataAnalytics #BeginnerFriendly #TechJourney #Consistency #WomenInTech

🚀 Day 2 of My SQL Learning Journey Today I learned about the WHERE clause in SQL. 👉 WHERE is used to filter data based on specific conditions. Basic syntax: SELECT column_name FROM table_name WHERE condition; ✔ Helps in retrieving only the required data ✔ Can be used with operators like =, >, <, AND, OR 💡 Learning WHERE made me realize how powerful SQL is when working with large datasets. Excited to keep improving! 🔥 Next: INSERT statement 👀 #SQL #LearningJourney #Beginner #DataAnalytics #Day2 #LearnInPublic

SQL felt confusing when I first learned it. Not because it was impossible. Because I was trying to learn it the wrong way. At first, I treated SQL like a list of commands to memorize:  • SELECT  • WHERE  • GROUP BY  • JOIN But that approach never really clicked. What helped me was this shift: I stopped thinking about syntax first. And started thinking about questions. 𝗙𝗼𝗿 𝗲𝘅𝗮𝗺𝗽𝗹𝗲:  • What data do I need?  • Which table has it?  • Do I need all rows or just some?  • Am I summarizing or combining data? That made SQL feel less like code and more like a conversation with the database. A few things helped me a lot:  • Practicing with small tables  • Writing one query pattern at a time  • Reading queries written by other people  • Focusing on business questions, not just syntax SQL got easier when I stopped trying to be fast and focused on being clear. That was the turning point. CTA: 𝗜𝗳 𝘆𝗼𝘂’𝗿𝗲 𝗹𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗦𝗤𝗟 𝗿𝗶𝗴𝗵𝘁 𝗻𝗼𝘄, 𝘄𝗵𝗮𝘁 𝗽𝗮𝗿𝘁 𝘀𝘁𝗶𝗹𝗹 𝗳𝗲𝗲𝗹𝘀 𝗰𝗼𝗻𝗳𝘂𝘀𝗶𝗻𝗴? #SQL #LearningJourney #DataAnalytics #CareerGrowth #DataScience

SQL isn’t just about writing queries… it’s about understanding how data really works. From SELECT, JOINs, and WHERE → to functions, keys, and performance — everything connects like layers of a cake 🍰 The more you explore, the more powerful your queries become. Still learning, still querying 🚀 #SQL #DataAnalytics #Learning #Database

Just wrapped up my handwritten notes on SQL ✍️ There’s something different about writing concepts by hand—it really helps them stick. Revisited core topics like queries, joins, and normalization. Focused on understanding rather than just memorizing. Breaking things down step by step made complex topics easier. Consistency is slowly turning into confidence. Still learning, still improving every day. Next step: applying these concepts in real projects. Open to tips, suggestions, and feedback from the community. #SQL #LearningJourney #TechSkills #DeveloperLife #Database #KeepLearning #Consistency #CodingJourney #Growth

SQL is more than just code; it’s a tool for curiosity. 🔍 I just wrapped up a deep dive into SQL foundations. Instead of just following tutorials, I focused on real-world applications—asking questions of the data and building queries to find the answers. What I’ve been building: ✅ Multi-table JOINs to calculate total revenue. ✅ GROUP BY & COUNT logic to track yearly order volumes. ✅ Data segmentation using CASE statements for payment analysis. ✅ Clean reporting using DISTINCT and specific filtering. The goal wasn't just to get the query to "run," but to make it efficient and meaningful. Next stop: Window Functions and Subqueries! 🚀 #DataScience #SQL #LearningPublic #DataAnalyst #TechJourney

My First SQL Query Took 30 Minutes It was simple. But I had no idea what I was doing. Now it takes 2 minutes. The difference? Not intelligence. Just repetition. If you're learning SQL: You're not behind. You're exactly where you should be! #SQL #DataAnalytics #Learning