Data Analytics & AI | SQL Interviews | Power BI Resources
๐Explore the fascinating world of Data Analytics & Artificial Intelligence ๐ป Best AI tools, free resources, and expert advice to land your dream tech job. Admin: @coderfun Buy ads: https://telega.io/c/Data_Visual
Show more๐ Analytical overview of Telegram channel Data Analytics & AI | SQL Interviews | Power BI Resources
Channel Data Analytics & AI | SQL Interviews | Power BI Resources (@data_visual) in the English language segment is an active participant. Currently, the community unites 27 206 subscribers, ranking 7 213 in the Education category and 15 999 in the India region.
๐ Audience metrics and dynamics
Since its creation on ะฝะตะฒัะดะพะผะพ, the project has demonstrated rapid growth, gathering an audience of 27 206 subscribers.
According to the latest data from 13 June, 2026, the channel demonstrates stable activity. Although there has been a change in the number of participants by 226 over the last 30 days and by 5 over the last 24 hours, overall reach remains high.
- Verification status: Not verified
- Engagement rate (ER): The average audience engagement rate is 3.99%. Within the first 24 hours after publication, content typically collects N/A% reactions from the total number of subscribers.
- Post reach: On average, each post receives 0 views. Within the first day, a publication typically gains 0 views.
- Reactions and interaction: The audience actively supports content: the average number of reactions per post is 0.
- Thematic interests: Content is focused on key topics such as |--, sql, learning, analytic, visualization.
๐ Description and content policy
The author describes the resource as a platform for expressing subjective opinions:
โ๐Explore the fascinating world of Data Analytics & Artificial Intelligence
๐ป Best AI tools, free resources, and expert advice to land your dream tech job.
Admin: @coderfun
Buy ads: https://telega.io/c/Data_Visualโ
Thanks to the high frequency of updates (latest data received on 14 June, 2026), the channel maintains relevance and a high level of publication reach. Analytics show that the audience actively interacts with content, making it an important point of influence in the Education category.
CASE statement to handle NULL values, use COALESCE():
SELECT COALESCE(name, 'Unknown') FROM users;
This returns the first non-null value in the list.
2๏ธโฃ Generate Sequential Numbers Without a Table
Need a sequence of numbers but donโt have a numbers table? Use GENERATE_SERIES (PostgreSQL) or WITH RECURSIVE (MySQL 8+):
SELECT generate_series(1, 10);
3๏ธโฃ Find Duplicates Quickly
Easily identify duplicate values with GROUP BY and HAVING:
SELECT email, COUNT(*)
FROM users
GROUP BY email
HAVING COUNT(*) > 1;
4๏ธโฃ Randomly Select Rows
Want a random sample of data? Use:
- PostgreSQL: ORDER BY RANDOM()
- MySQL: ORDER BY RAND()
- SQL Server: ORDER BY NEWID()
5๏ธโฃ Pivot Data Without PIVOT (For Databases Without It)
Use CASE with SUM() to pivot data manually:
SELECT
user_id,
SUM(CASE WHEN status = 'active' THEN 1 ELSE 0 END) AS active_count,
SUM(CASE WHEN status = 'inactive' THEN 1 ELSE 0 END) AS inactive_count
FROM users
GROUP BY user_id;
6๏ธโฃ Efficiently Get the Last Inserted ID
Instead of running a separate SELECT, use:
- MySQL: SELECT LAST_INSERT_ID();
- PostgreSQL: RETURNING id;
- SQL Server: SELECT SCOPE_IDENTITY();
Like for more โค๏ธ๐ฉโ๐ผ: โWe want to decrease user churn by 5% this quarterโWe say that a user churns when she decides to stop using Uber. But why? There are different reasons why a user would stop using Uber. For example: 1. โLyft is offering better prices for that geoโ (pricing problem) 2. โCar waiting times are too longโ (supply problem) 3. โThe Android version of the app is very slowโ (client-app performance problem) You build this list โ by asking the right questions to the rest of the team. You need to understand the userโs experience using the app, from HER point of view. Typically there is no single reason behind churn, but a combination of a few of these. The question is: which one should you focus on? This is when you pull out your great data science skills and EXPLORE THE DATA ๐. You explore the data to understand how plausible each of the above explanations is. The output from this analysis is a single hypothesis you should consider further. Depending on the hypothesis, you will solve the data science problem differently. For exampleโฆ Scenario 1: โLyft Is Offering Better Pricesโ (Pricing Problem) One solution would be to detect/predict the segment of users who are likely to churn (possibly using an ML Model) and send personalized discounts via push notifications. To test your solution works, you will need to run an A/B test, so you will split a percentage of Uber users into 2 groups: The A group. No user in this group will receive any discount. The B group. Users from this group that the model thinks are likely to churn, will receive a price discount in their next trip. You could add more groups (e.g. C, D, Eโฆ) to test different pricing points.
In a nutshell1. Translating business problems into data science problems is the key data science skill that separates a senior from a junior data scientist. 2. Ask the right questions, list possible solutions, and explore the data to narrow down the list to one. 3. Solve this one data science problem
Available now! Telegram Research 2025 โ the year's key insights 
