How Useful Is Good SQL Writing and How Deep Should You Master It?

Is writing good SQL useful for data development, and to what extent should one master it?

This question is frequently asked by members of my Knowledge Planet community, and I’ll answer it briefly today.

First, the answer varies across different scenarios and may differ from common expectations.

I will address the question from both a macro perspective and specific use cases.

In everyday work, data development has become largely SQL‑centric, with high integration and ease of use being top priorities for any framework.

Therefore, SQL is a fundamental skill unavoidable in any direction, similar to how backend developers must be proficient in CRUD operations.

The issue is that while SQL is a basic skill, the question becomes how deep to master it and how much effort to invest.

If you can handle interview SQL questions, don’t spend extra effort on writing better SQL.

Your time should be allocated to newer, more advanced data‑development tech stacks, which most people lack; over 80% of my 700+ mentees had outdated stacks, not lacking SQL basics.

Moreover, the rise of ChatGPT and AI‑assisted programming has further reduced the importance of basic SQL skills.

Thus, making excellent SQL a major goal is unnecessary.

Because the market value of this ability is limited.

As AIGC evolves, the value of SQL diminishes, while mastering prompts and AI interaction becomes more important.

For fresh graduates, solid SQL basics are still important for campus recruitment, as interview SQL questions are low difficulty and low learning cost.

Finally, regarding SQL assessment in social recruitment, if your goal is only interview preparation, a quick crash course suffices.

Because in work SQL is used daily and interview patterns are predictable; failing an interview is rarely due to SQL performance.

In 99% of cases, a company won’t reject a candidate solely for SQL; it accounts for less than 10% of interview weight.

Different opinions are fine; they show independent thinking.

Lastly, feel free to ask me questions on the Knowledge Planet platform, especially direction‑related ones, where a single answer can save you many detours.