SQL_feed's profile picture. Learn. Query. Automate. | Daily SQL tips & data wisdom.

World of SQL

@SQL_feed

Learn. Query. Automate. | Daily SQL tips & data wisdom.

Pinned

Learn SQL the simple, visual, and practical way. Clear concepts. Real-world examples. Python + SQL. Automation. Everything you need to level up your data skills. Follow @SQL_feed.


Python + SQL is one of the most useful skills in data work. Python doesn’t replace SQL, it automates everything around it. Here’s what Python can automate for you: • Running recurring SQL queries • Loading results into Pandas/DataFrames • Cleaning and transforming data •…


When to Use Each Python SQL Library 🔹 SQLAlchemy — Use it when… •You’re building an app •You want models (ORM) •You need reusable queries •You don’t want to manually write SQL every time Best for: automation, pipelines, web apps. ⸻ 🔹 Pandas (read_sql) — Use it when……


Python Libraries Every SQL User Should Know 🔹 1. SQLAlchemy The most powerful Python ORM + query builder. Used for database models, sessions, and generating SQL automatically. 🔹 2. Pandas (pd.read_sql) Pandas can run SQL queries directly and load results…


SQL is the language. SQLAlchemy is the toolbox that lets Python speak that language safely and powerfully. With SQL, you write queries. With SQLAlchemy, you build queries dynamically, programmatically, and database-agnostically. Same result. Different mindset. Perfect combo for…


Understanding GROUP BY in SQL (Deep Dive) GROUP BY lets you summarize data by categories and it’s essential for reporting, analytics, and dashboards. Once you master GROUP BY, you can transform raw tables into real insights. 📊 #SQL #DataAnalytics #DataEngineering #LearnSQL

SQL_feed's tweet image. Understanding GROUP BY in SQL (Deep Dive)

GROUP BY lets you summarize data by categories and it’s essential for reporting, analytics, and dashboards.

Once you master GROUP BY, you can transform raw tables into real insights. 📊

#SQL #DataAnalytics #DataEngineering #LearnSQL

Understanding NULLs in SQL - What They REALLY Mean NULL isn’t zero. NULL isn’t empty. NULL means “unknown” and it behaves differently from any other value in SQL. Here’s what to remember: = and <> don’t work with NULL Always use IS NULL / IS NOT NULL Functions like COALESCE…

SQL_feed's tweet image. Understanding NULLs in SQL - What They REALLY Mean

NULL isn’t zero.
NULL isn’t empty.
NULL means “unknown” and it behaves differently from any other value in SQL.
Here’s what to remember:
= and &amp;lt;&amp;gt; don’t work with NULL

Always use IS NULL / IS NOT NULL

Functions like COALESCE…

COALESCE in SQL - Handle NULLs the Smart Way COALESCE() returns the first non-NULL value in a list. It’s one of the simplest and most powerful tools for cleaning data. Use it to: - Replace NULLs with defaults - Prevent calculation errors - Keep reports clean - Evaluate multiple…

SQL_feed's tweet image. COALESCE in SQL - Handle NULLs the Smart Way

COALESCE() returns the first non-NULL value in a list.
It’s one of the simplest and most powerful tools for cleaning data.
Use it to:

- Replace NULLs with defaults
- Prevent calculation errors
- Keep reports clean
- Evaluate multiple…

The Anatomy of a SELECT Query (Deep Dive) Every SQL query follows a predictable structure. Once you understand the order of each clause, writing clean queries becomes effortless. Here’s the full flow: SELECT → choose columns FROM → choose table WHERE → filter rows GROUP BY…

SQL_feed's tweet image. The Anatomy of a SELECT Query (Deep Dive)

Every SQL query follows a predictable structure.
Once you understand the order of each clause, writing clean queries becomes effortless.
Here’s the full flow:

SELECT → choose columns
FROM → choose table
WHERE → filter rows
GROUP BY…

SELECT in SQL - Your Most Important Command Every SQL journey starts with SELECT. It lets you extract exactly the data you need - columns, filters, ordering, and more. Mastering SELECT is the first step toward mastering SQL. #SQL #DataAnalytics #DataEngineering #LearnSQL

SQL_feed's tweet image. SELECT in SQL - Your Most Important Command

Every SQL journey starts with SELECT.
It lets you extract exactly the data you need - columns, filters, ordering, and more.
Mastering SELECT is the first step toward mastering SQL.

#SQL #DataAnalytics #DataEngineering #LearnSQL

What is SQLAlchemy? SQLAlchemy lets you work with databases like writing Python code, not raw SQL. It’s perfect when you want: - Cleaner, more readable queries - Python objects instead of strings - Safer database interactions - A scalable way to build data apps If you use…

SQL_feed's tweet image. What is SQLAlchemy?

SQLAlchemy lets you work with databases like writing Python code, not raw SQL.

It’s perfect when you want:
- Cleaner, more readable queries
- Python objects instead of strings
- Safer database interactions
- A scalable way to build data apps
If you use…

Why Analysts Use Python with SQL SQL gets the data. Python transforms it. Together → they create powerful, automated, repeatable workflows. If you want to level up as an analyst, learning both is a game-changer. #SQL #Python #DataEngineering #DataAnalytics

SQL_feed's tweet image. Why Analysts Use Python with SQL

SQL gets the data. Python transforms it.
Together → they create powerful, automated, repeatable workflows. If you want to level up as an analyst, learning both is a game-changer.

#SQL #Python #DataEngineering #DataAnalytics

SQL Joins Explained (Visual Guide) Understanding joins is essential for working with relational databases: Left Join → All rows from the left table + matches from the right Right Join → All rows from the right table + matches from the left Inner Join → Only matching rows…

SQL_feed's tweet image. SQL Joins Explained (Visual Guide)

Understanding joins is essential for working with relational databases:

Left Join → All rows from the left table + matches from the right
Right Join → All rows from the right table + matches from the left
Inner Join → Only matching rows…

Common SQL Mistake: WHERE vs. HAVING WHERE filters rows before aggregation. HAVING filters after aggregation. If you’re using COUNT(), SUM(), AVG(), etc. → You almost always need HAVING, not WHERE. Master this and you’ll avoid one of the easiest SQL traps. #SQL

SQL_feed's tweet image. Common SQL Mistake: WHERE vs. HAVING

WHERE filters rows before aggregation.
HAVING filters after aggregation.
If you’re using COUNT(), SUM(), AVG(), etc. →
You almost always need HAVING, not WHERE.

Master this and you’ll avoid one of the easiest SQL traps.

#SQL…

What is a Primary Key (PK)? A simple rule: every table needs one. It uniquely identifies each row and keeps your data structured, stable, and relational. Master this concept → you instantly understand 50% of SQL design. #SQL #DataEngineering #DataAnalytics

SQL_feed's tweet image. What is a Primary Key (PK)?

A simple rule: every table needs one.
It uniquely identifies each row and keeps your data structured, stable, and relational.

Master this concept → you instantly understand 50% of SQL design.

#SQL #DataEngineering #DataAnalytics

Window functions aren’t “advanced”, they’re your superpower once you learn them. Here’s the mental model: •GROUP BY → compresses rows •Window functions → keep rows and add calculations •Perfect for: rankings, running totals, moving averages, comparisons If you’re doing…


United States Trends

Loading...

Something went wrong.


Something went wrong.