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Josep Ferrer

@rfeers.bsky.social

Data Scientist & Tech Writer KDnuggets, DataCap, TDS & Medium | Outstand using data - Data Science, AI and Tech | Join 6k data professionals reading databites.tech ๐Ÿงฉ

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How to Actually Get Started with SQL CS16 - A clear (and human) guide to get started without drowning

START LEARNING

๐—ฆ๐—ค๐—Ÿ

RIGHT NOW!!

www.databites.tech/p/how-to-ac...

22.10.2025 12:08 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Then join the DataBites newsletter to get weekly issues about Data Science and more! ๐Ÿงฉ

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22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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How to Actually Get Started with SQL CS16 - A clear (and human) guide to get started without drowning

If you like this thread, go check the original articleโ€ผ๏ธ

www.databites.tech/p/how-to-ac...

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

15. ๐—”๐—ฑ๐˜ƒ๐—ฎ๐—ป๐—ฐ๐—ฒ๐—ฑ ๐—ฆ๐—ค๐—Ÿ ๐—ง๐—ฒ๐—ฐ๐—ต๐—ป๐—ถ๐—พ๐˜‚๐—ฒ๐˜€
For seasoned users, explore sophisticated SQL features:
โ€ข Windows Functions, Recursive Queries
โ€ข Pivot/Unpivot Operations, Common Table Expressions (CTE)

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

The two final steps is learning how to craft better and more optimized SQL queries.

14. ๐—ฃ๐—ฒ๐—ฟ๐—ณ๐—ผ๐—ฟ๐—บ๐—ฎ๐—ป๐—ฐ๐—ฒ ๐—ข๐—ฝ๐˜๐—ถ๐—บ๐—ถ๐˜‡๐—ฎ๐˜๐—ถ๐—ผ๐—ป
Techniques to enhance the efficiency of your queries:
โ€ข Query Analysis, Optimizing JOINS, Reducing Subqueries

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

13. ๐——๐—ฎ๐˜๐—ฎ ๐—œ๐—ป๐˜๐—ฒ๐—ด๐—ฟ๐—ถ๐˜๐˜† ๐—ฎ๐—ป๐—ฑ ๐—ฆ๐—ฒ๐—ฐ๐˜‚๐—ฟ๐—ถ๐˜๐˜†
Now that you are here, I strongly recommend you get familiar with security best practices. Maintain the security and integrity of your database:
โ€ข Using GRANT and REVOKE
โ€ข Database Security Best Practices

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Now you should focus on crafting better queries by leveraging indexes and following best security practices ๐Ÿ’ฅ

12. ๐—ข๐—ฝ๐˜๐—ถ๐—บ๐—ถ๐˜‡๐—ถ๐—ป๐—ด ๐˜„๐—ถ๐˜๐—ต ๐—œ๐—ป๐—ฑ๐—ฒ๐˜…๐—ฒ๐˜€
Indexes improve query performance:
โ€ข Unique, Clustered, and Non-Clustered Indexes

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Once a result is good, you might want to create a view!
11. ๐—ช๐—ผ๐—ฟ๐—ธ๐—ถ๐—ป๐—ด ๐˜„๐—ถ๐˜๐—ต ๐—ฉ๐—ถ๐—ฒ๐˜„๐˜€
Views can simplify complex queries:
โ€ข Creating, Modifying, and Dropping Views

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Now you should understand advanced syntax like specific functions and new ways of merging data like UNION.

10. ๐—”๐—ฑ๐˜ƒ๐—ฎ๐—ป๐—ฐ๐—ฒ๐—ฑ ๐—ฆ๐˜†๐—ป๐˜๐—ฎ๐˜…
Explore more complex SQL operations:
โ€ข UNION, INTERSECT, EXCEPT
โ€ข CASE, COALESCE, and Functions for NULL Handling

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Your SQL skills here are already really good!! ๐Ÿ™Œ๐Ÿป
But learning must go onโ€ฆ

9. ๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—ฟ๐—ฎ๐—ด๐—ถ๐—ป๐—ด ๐—ฆ๐˜‚๐—ฏ๐—พ๐˜‚๐—ฒ๐—ฟ๐—ถ๐—ฒ๐˜€
As queries keep getting more complex, you need to create subqueries.
โ€ข Nested and Correlated Subqueries
โ€ข EXISTS and NOT EXISTS

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Our data will usually be spread across many different tables, this is why being able to merge data from different sources is crucial in SQL.

8. ๐— ๐—ฎ๐˜€๐˜๐—ฒ๐—ฟ๐—ถ๐—ป๐—ด ๐—๐—ข๐—œ๐—ก๐˜€
JOINs are critical for combining data from multiple tables:
โ€ข INNER, LEFT, RIGHT, and FULL OUTER JOINs

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
Preview
How to Actually Get Started with SQL CS16 - A clear (and human) guide to get started without drowning

If you like this thread, go check the original articleโ€ผ๏ธ

www.databites.tech/p/how-to-ac...

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

๐Ÿ‘‰๐Ÿป This will be one of the most important steps when creating KPIs and specific metrics.

7. ๐—˜๐—ป๐—ณ๐—ผ๐—ฟ๐—ฐ๐—ถ๐—ป๐—ด ๐—–๐—ผ๐—ป๐˜€๐˜๐—ฟ๐—ฎ๐—ถ๐—ป๐˜๐˜€
Ensure data integrity through constraints:
โ€ข PRIMARY KEY, FOREIGN KEY, UNIQUE
โ€ข NOT NULL and CHECK Constraints

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Now you should keep getting better with SQL programming language ๐Ÿ’ฅ

6. ๐—จ๐—ป๐—ฑ๐—ฒ๐—ฟ๐˜€๐˜๐—ฎ๐—ป๐—ฑ๐—ถ๐—ป๐—ด ๐—”๐—ด๐—ด๐—ฟ๐—ฒ๐—ด๐—ฎ๐˜๐—ถ๐—ผ๐—ป
Aggregate functions are powerful tools for summarizing data:
โ€ข SUM, AVG, COUNT, MAX, MIN

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

5. ๐——๐—ฎ๐˜๐—ฎ ๐— ๐—ฎ๐—ป๐—ถ๐—ฝ๐˜‚๐—น๐—ฎ๐˜๐—ถ๐—ผ๐—ป
Get hands-on with inserting, updating, and deleting data:
โ€ข INSERT, UPDATE, DELETE Commands

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Already proficient with basic commands?

Now itโ€™s turn to understand how to manage databases with the following two steps:

4. ๐——๐—ฎ๐˜๐—ฎ ๐——๐—ฒ๐—ณ๐—ถ๐—ป๐—ถ๐˜๐—ถ๐—ผ๐—ป
Learn how to structure and manage your databases with:
โ€ข CREATE, ALTER, DROP Statements

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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3. ๐— ๐—ฎ๐˜€๐˜๐—ฒ๐—ฟ๐—ถ๐—ป๐—ด ๐—•๐—ฎ๐˜€๐—ถ๐—ฐ ๐—ž๐—ฒ๐˜†๐˜„๐—ผ๐—ฟ๐—ฑ๐˜€
The first real step is to familiarize yourself with the commands that form the backbone of SQL querying:

โ€ข SELECT, FROM, WHERE
โ€ข ORDER BY and LIMIT Clauses

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

2. ๐—˜๐˜…๐—ฝ๐—น๐—ผ๐—ฟ๐—ถ๐—ป๐—ด ๐——๐—ฎ๐˜๐—ฎ ๐—ง๐˜†๐—ฝ๐—ฒ๐˜€
Once you have a clear image of SQL, you should understand the core data types you will be working with ๐Ÿ‘‡๐Ÿป

โ€ข Integers, Decimals, and Booleans
โ€ข Character Types: CHAR and VARCHAR
โ€ข Dates and Binary Data

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
Preview
How to Actually Get Started with SQL CS16 - A clear (and human) guide to get started without drowning

If you like this thread, go check the original articleโ€ผ๏ธ

www.databites.tech/p/how-to-ac...

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

1. ๐—Ÿ๐—ฒ๐—ฎ๐—ฟ๐—ป๐—ถ๐—ป๐—ด ๐˜๐—ต๐—ฒ ๐—•๐—ฎ๐˜€๐—ถ๐—ฐ๐˜€
Before diving deep, it's essential to grasp what is SQL.

Begin with:
โ€ข What is a Relational Database?
โ€ข Comparing SQL and NoSQL Databases
โ€ข Understanding SQL Syntax and Basic Commands

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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๐Ÿš€ New to SQL?

Then hereโ€™s a roadmap to get you started in 2025, step-by-step! ๐Ÿงต๐Ÿ‘‡

(Don't forget to bookmark for later!! ๐Ÿ˜‰ )

22.10.2025 10:35 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Did you like this post?

Then join the DataBites newsletter to get weekly issues about Data Science and more! ๐Ÿงฉ

๐Ÿ‘‰๐Ÿป databites.tech

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

This roadmap covers everything you need to go from a beginner to an advanced Python programmer! ๐ŸŒฑ

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

17. ๐——๐—ฒ๐˜ƒ๐—ข๐—ฝ๐˜€ ๐—ฎ๐—ป๐—ฑ ๐——๐—ฒ๐—ฝ๐—น๐—ผ๐˜†๐—บ๐—ฒ๐—ป๐˜
Integrate Python into DevOps practices to deploy and scale your applications. Understanding CI/CD, Docker, and cloud deployment will make your skills industry-ready.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

16. ๐—ง๐—ฒ๐˜€๐˜๐—ถ๐—ป๐—ด
Testing is essential for reliable software! Learn the basics of Doctest, Nose, Pytest, and Unittest. These tools help ensure that your code works as expected.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

15. ๐—–๐—ผ๐—บ๐—บ๐—ผ๐—ป ๐—ฃ๐—ฎ๐—ฐ๐—ธ๐—ฎ๐—ด๐—ฒ๐˜€
Familiarize yourself with essential packages like typing for type hints and tox for testing multiple environments. These are invaluable for robust, maintainable code.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

14. ๐——๐—ผ๐—ฐ๐˜‚๐—บ๐—ฒ๐—ป๐˜๐—ฎ๐˜๐—ถ๐—ผ๐—ป
Documenting your code is crucial for clarity and collaboration. Learn to use Sphinx to generate beautiful, automated documentation that helps others understand your code.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

13. ๐—–๐—ผ๐—ฑ๐—ฒ ๐—™๐—ผ๐—ฟ๐—บ๐—ฎ๐˜๐˜๐—ถ๐—ป๐—ด
Clean, readable code is a must! Use tools like Black, YAPF, and Ruff to maintain consistent formatting across your projects. Itโ€™s a small habit that makes a big difference.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

12. ๐—ฆ๐˜๐—ฎ๐˜๐—ถ๐—ฐ ๐—ง๐˜†๐—ฝ๐—ถ๐—ป๐—ด
Enhance readability and reduce errors with static typing! Libraries like Pydantic, Mypy, Pyright, and Pyre bring optional type hints to Python, making your code safer and easier to understand.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

11. ๐— ๐—ฎ๐—ป๐—ฎ๐—ด๐—ฒ ๐—˜๐—ป๐˜ƒ๐—ถ๐—ฟ๐—ผ๐—ป๐—บ๐—ฒ๐—ป๐˜๐˜€
Keep your projects organized! Use tools like Virtualenv, Pyenv, and Pipenv to manage different Python environments and dependencies for each project.

15.10.2025 10:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0