How to Write SQL That Everyone Can Understand

Posted on:September 22, 2025

Welcome, Developer 👋

Recently, I’ve been working on some complex SQL queries for real-world projects. What I noticed is that every developer seems to have their own style. Some queries were neatly formatted, others were crammed into a single line, and more than once, I found myself spending extra time just trying to understand what the query was doing.

That experience made me realize something: writing readable SQL is a skill in itself. It’s not only about getting the query to work; it’s about making sure other developers (and your future self) can understand it quickly.

That’s why I decided to put together this post — a collection of best practices for writing SQL that everyone can understand.

Intro

Anyone can write SQL — but not everyone writes readable SQL. If you’ve ever opened a query full of nested subqueries, cryptic column names, and zero indentation, you know the pain.

Readable SQL isn’t just about aesthetics. It helps:

In this post, we’ll explore eight best practices that make your SQL queries clear, professional, and maintainable.

1. Format and Indent Your Queries

Formatting is the easiest readability win. Line breaks and indentation make structure obvious.

❌ Hard to read:

SELECT c.id,c.name,o.id,o.amount FROM customers c JOIN orders o ON c.id=o.customer_id WHERE o.amount>1000 ORDER BY o.amount DESC;

✅ Readable:

SELECT
    c.id,
    c.name,
    o.id AS order_id,
    o.amount
FROM customers c
JOIN orders o
    ON c.id = o.customer_id
WHERE o.amount > 1000
ORDER BY o.amount DESC;

👉 Pro tip: use a SQL formatter (built into most IDEs) to keep your queries consistent.

2. Use Aliases and Meaningful Column Names

Aliases save typing, but don’t overdo it. Short aliases (c, o) are fine, but avoid meaningless names like col1 or cte1.

Better: use descriptive aliases and column names.

SELECT
    cust.id AS customer_id,
    cust.name AS customer_name,
    ord.id AS order_id,
    ord.amount AS order_total
FROM customers AS cust
JOIN orders AS ord
    ON cust.id = ord.customer_id;

Now the query is self-explanatory, even to someone new to the database.

3. Split Logic with CTEs

When a query has too many nested subqueries, it becomes spaghetti. CTEs (Common Table Expressions) let you break complex logic into readable steps.

Without CTE (messy):

SELECT c.name, SUM(o.amount)
FROM customers c
JOIN (
    SELECT customer_id, amount
    FROM orders
    WHERE status = 'completed'
) o ON c.id = o.customer_id
GROUP BY c.name;

With CTE (clear):

WITH completed_orders AS (
    SELECT customer_id, amount
    FROM orders
    WHERE status = 'completed'
)
SELECT
    c.name,
    SUM(o.amount) AS total_spent
FROM customers c
JOIN completed_orders o
    ON c.id = o.customer_id
GROUP BY c.name;

👉 Using CTEs makes queries step-by-step stories instead of puzzles.

4. Comment Your Queries

SQL is often the “last mile” of business logic. Comments help explain why you’re filtering or aggregating a certain way.

-- Find customers who spent more than $1000 in completed orders
WITH completed_orders AS (
    SELECT customer_id, amount
    FROM orders
    WHERE status = 'completed'
)
SELECT
    c.name,
    SUM(o.amount) AS total_spent
FROM customers c
JOIN completed_orders o
    ON c.id = o.customer_id
WHERE SUM(o.amount) > 1000
GROUP BY c.name;

Even if the query is simple, a one-line comment can save hours of head-scratching later.

5. Keep SQL Keywords Consistent

Should you write select or SELECT? Both work, but consistency matters.

Most teams prefer uppercase for SQL keywords and lowercase for identifiers. This makes queries easier to scan.

Example:

SELECT name, email
FROM customers
WHERE status = 'active';

6. Avoid SELECT *

It’s tempting to select everything, but it can lead to:

Better: always specify the columns you need.

7. Order Your Clauses Logically

Follow a consistent order of clauses. The most common (and easiest to read) is:

SELECT → FROM → JOIN → WHERE → GROUP BY → HAVING → ORDER BY → LIMIT

Example:

SELECT product_id, SUM(quantity) AS total_sold
FROM order_items
WHERE created_at >= '2025-01-01'
GROUP BY product_id
HAVING SUM(quantity) > 10
ORDER BY total_sold DESC
LIMIT 5;

8. Team Conventions and Tools

If you’re writing SQL as part of a team:

Readable SQL is a team habit, not just an individual skill.

9. Free and Open-Source SQL IDEs to Try

Readable SQL also depends on the tools you use. A good SQL IDE can format queries automatically, highlight syntax, and even lint your code. Here are some solid free and open-source options:

DBeaver – ⭐ 36k+ stars on GitHub, one of the most popular database tools. Multi-platform, supports almost every database, powerful SQL formatting.

Beekeeper Studio – ⭐ 15k+ stars on GitHub. Modern, clean interface. Great for PostgreSQL, MySQL, and SQLite.

pgAdmin – The official PostgreSQL admin tool, bundled with many PostgreSQL installations. Highly trusted and widely adopted.

If you’re not sure where to start, DBeaver and Beekeeper Studio are excellent beginner-friendly choices, while pgAdmin is the best pick if you work primarily with PostgreSQL.

Conclusion

SQL is not just for the database engine — it’s for people too. Writing clean, readable SQL makes collaboration smoother, debugging faster, and maintenance easier.

Next time you write a query, remember:

Your teammates (and your future self) will thank you!