📝[Docs]: Add SQL Advanced Analytical & BI Features docs

[dinesh-2047]

Is there an existing issue for this?

• I have searched the existing issues

Issue Description

i would like to add SQL Advanced Analytical & BI Features (Advance topics), Kindly assign this issue to me and also add label of hacktoberfest .

Suggested Change

Add - Advanced Analytical & BI Features
1.GROUPING SETS, CUBE, ROLLUP
2.Pivot & Unpivot queries
3.Percentiles, ranking, moving averages

Rationale

No response

Urgency

Medium

Record

• I have read the Contributing Guidelines
• Are you a GSSOC'25 contributor
• I want to work on this issue

[github-actions]

Thanks for opening this issue! 🎉 We'll look into it as soon as possible, estimated time for response is 5–8 hrs.

Don't raise PR unless assigned to you.

In the meantime, please provide all necessary details and context to your issue — screenshots or videos of your changes help speed up the review and assignment. If you have questions, reach out to LinkedIn. Your contributions are highly appreciated!😊

Note: I maintain the repo issue every day twice at 8:00 AM IST and 9:00 PM IST. If your issue goes stale for more than one day, you can tag and comment on this same issue by tagging @sanjay-kv.

We are here to help you on this journey of open source. Consistent contributions are eligible for sponsorship 💰

🎁 check our list of amazing people we sponsored so far: GitHub Sponsorship. ✨

📚Resources which can help you know more about Github 👇🏻

1. End to End GitHub Beginner Playlist: GitHub Playlist.

2. Build your GitHub Profile: GitHub Profile Optimisation.

3. GitHub Handbook for dummies: GitHub Blog for Beginners.

[github-actions]

👤 Issue assigned to @dinesh-2047.