Data Analyst Interview Resources
Join our telegram channel to learn how data analysis can reveal fascinating patterns, trends, and stories hidden within the numbers! 📊 For ads & suggestions: @love_data
نمایش بیشتر📈 تحلیل کانال تلگرام Data Analyst Interview Resources
کانال Data Analyst Interview Resources (@dataanalystinterview) در بخش زبانی انگلیسی بازیگری فعال است. در حال حاضر جامعه شامل 52 246 مشترک است و جایگاه 3 340 را در دسته آموزش و رتبه 7 201 را در منطقه الهند دارد.
📊 شاخصهای مخاطب و پویایی
از زمان ایجاد در невідомо، پروژه رشد سریعی داشته و 52 246 مشترک جذب کرده است.
بر اساس آخرین دادهها در تاریخ 09 ژوئن, 2026، کانال فعالیت پایداری دارد. در ۳۰ روز گذشته تغییر اعضا برابر 230 و در ۲۴ ساعت گذشته برابر 12 بوده و همچنان دسترسی گستردهای حفظ شده است.
- وضعیت تأیید: تأیید نشده
- نرخ تعامل (ER): میانگین تعامل مخاطب 2.30% است و در ۲۴ ساعت نخست پس از انتشار، محتوا معمولاً 0.91% واکنش نسبت به کل مشترکان کسب میکند.
- دسترسی پستها: هر پست به طور میانگین 1 202 بازدید دریافت میکند. در اولین روز معمولاً 473 بازدید جمعآوری میشود.
- واکنشها و تعامل: مخاطبان بهطور فعال حمایت میکنند؛ میانگین واکنش به هر پست 3 است.
- علایق موضوعی: محتوا بر موضوعات کلیدی مانند sql, row, |--, dataset, visualization تمرکز دارد.
📝 توضیح و سیاست محتوایی
نویسنده این فضا را محل بیان دیدگاههای شخصی توصیف میکند:
“Join our telegram channel to learn how data analysis can reveal fascinating patterns, trends, and stories hidden within the numbers! 📊
For ads & suggestions: @love_data”
به لطف بهروزرسانیهای پرتکرار (آخرین داده در تاریخ 10 ژوئن, 2026)، کانال همواره بهروز و دارای دسترسی بالاست. تحلیلها نشان میدهد مخاطبان بهطور فعال با محتوا تعامل دارند و آن را به نقطه اثرگذاری مهم در دسته آموزش تبدیل کردهاند.
RANK() to include ties
❤️ React for more questionsDENSE_RANK() or ROW_NUMBER()
👉 Filter where rank = N
👉 Handle duplicates carefully
📊 Q2. Find common records between two tables?
👉 Use INNER JOIN
👉 Or INTERSECT (if supported)
👉 Based on matching columns
📊 Q3. Find records present in both tables but with different values?
👉 JOIN on key
👉 Compare columns in WHERE
👉 Useful for data mismatch checks
📊 Q4. Count number of orders per day + running total?
👉 GROUP BY order_date
👉 Use SUM() OVER (ORDER BY date)
📊 Q5. Find users who never placed any order?
👉 LEFT JOIN orders
👉 Filter WHERE order_id IS NULL
👉 Or use NOT EXISTS
📊 Q6. How do you delete duplicate rows but keep one?
👉 Use ROW_NUMBER() with PARTITION BY
👉 Delete where row_number > 1
👉 Always test with SELECT first ⚠️
👉 Backup before deleting
🔥 React with ❤️ for more such questionsMIN() in a CTE
✅ Join carefully on both user_id + date to avoid false matches
❤️ React with a ❤️ for more interview questionsSUM() OVER()
👉 PARTITION BY (optional)
👉 ORDER BY for sequence
📊 Top N records per group?
👉 Use ROW_NUMBER() / RANK()
👉 PARTITION BY category
👉 Filter where rank ≤ N
📊 Find duplicate records?
👉 GROUP BY + HAVING COUNT(*) > 1
👉 Or use ROW_NUMBER()
👉 Helps in data cleaning
📊 Delete duplicate rows (keep one)?
👉 Use CTE + ROW_NUMBER()
👉 Delete where row_num > 1
👉 Keep latest/oldest using ORDER BY
📊 Employees earning more than their manager?
👉 Self JOIN on employee table
👉 Compare employee salary > manager salary
👉 Classic interview favorite
🔥 React ♥️ if you want Part 4NULLs, constraints
🧠 Interview Tip: Be able to explain Primary vs Foreign Key.
2️⃣ Basic Queries
🔹 SELECT, FROM, WHERE, ORDER BY, LIMIT
🧠 Practice: Filter and sort data by multiple columns.
3️⃣ Joins – Very Frequently Asked!
🔹 INNER, LEFT, RIGHT, FULL OUTER JOIN
🧠 Interview Tip: Explain the difference with examples.
🧪 Practice: Write queries using joins across 2–3 tables.
4️⃣ Aggregations & GROUP BY
🔹 COUNT, SUM, AVG, MIN, MAX, HAVING
🧠 Common Question: Total sales per category where total > X.
5️⃣ Window Functions
🔹 ROW_NUMBER(), RANK(), DENSE_RANK(), LAG(), LEAD()
🧠 Interview Favorite: Top N per group, previous row comparison.
6️⃣ Subqueries & CTEs
🔹 Write queries inside WHERE, FROM, and using WITH
🧠 Use Case: Filtering on aggregated data, simplifying logic.
7️⃣ CASE Statements
🔹 Add logic directly in SELECT
🧠 Example: Categorize users based on spend or activity.
8️⃣ Data Cleaning & Transformation
🔹 Handle NULLs, format dates, string manipulation (TRIM, SUBSTRING)
🧠 Real-world Task: Clean user input data.
9️⃣ Query Optimization Basics
🔹 Understand indexing, query plan, performance tips
🧠 Interview Tip: Difference between WHERE and HAVING.
🔟 Real-World Scenarios
🧠 Must Practice:
• Sales funnel
• Retention cohort
• Churn rate
• Revenue by channel
• Daily active users
🧪 Practice Platforms
• LeetCode (Easy–Hard SQL)
• StrataScratch (Real business cases)
• Mode Analytics (SQL + Visualization)
• HackerRank SQL (MCQs + Coding)
💼 Final Tip:
Explain why your query works, not just what it does. Speak your logic clearly.
💬 Tap ❤️ for more!CREATE DATABASE db_name;
- USE db_name;
2. Tables
- Create Table: CREATE TABLE table_name (col1 datatype, col2 datatype);
- Drop Table: DROP TABLE table_name;
- Alter Table: ALTER TABLE table_name ADD column_name datatype;
3. Insert Data
- INSERT INTO table_name (col1, col2) VALUES (val1, val2);
4. Select Queries
- Basic Select: SELECT * FROM table_name;
- Select Specific Columns: SELECT col1, col2 FROM table_name;
- Select with Condition: SELECT * FROM table_name WHERE condition;
5. Update Data
- UPDATE table_name SET col1 = value1 WHERE condition;
6. Delete Data
- DELETE FROM table_name WHERE condition;
7. Joins
- Inner Join: SELECT * FROM table1 INNER JOIN table2 ON table1.col = table2.col;
- Left Join: SELECT * FROM table1 LEFT JOIN table2 ON table1.col = table2.col;
- Right Join: SELECT * FROM table1 RIGHT JOIN table2 ON table1.col = table2.col;
8. Aggregations
- Count: SELECT COUNT(*) FROM table_name;
- Sum: SELECT SUM(col) FROM table_name;
- Group By: SELECT col, COUNT(*) FROM table_name GROUP BY col;
9. Sorting & Limiting
- Order By: SELECT * FROM table_name ORDER BY col ASC|DESC;
- Limit Results: SELECT * FROM table_name LIMIT n;
10. Indexes
- Create Index: CREATE INDEX idx_name ON table_name (col);
- Drop Index: DROP INDEX idx_name;
11. Subqueries
- SELECT * FROM table_name WHERE col IN (SELECT col FROM other_table);
12. Views
- Create View: CREATE VIEW view_name AS SELECT * FROM table_name;
- Drop View: DROP VIEW view_name;
اکنون در دسترس! پژوهش تلگرام ۲۰۲۵ — مهمترین بینشهای سال 
