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
Mostrar más📈 Análisis del canal de Telegram Data Analyst Interview Resources
El canal Data Analyst Interview Resources (@dataanalystinterview) en el segmento lingüístico de Inglés es un actor destacado. Actualmente la comunidad reúne a 52 280 suscriptores, ocupando la posición 3 330 en la categoría Educación y el puesto 7 186 en la región India.
📊 Métricas de audiencia y dinámica
Desde su creación el невідомо, el proyecto ha mostrado un crecimiento acelerado, reuniendo a 52 280 suscriptores.
Según los últimos datos del 11 junio, 2026, el canal mantiene una actividad estable. En los últimos 30 días la variación de miembros fue de 247, y en las últimas 24 horas de 13, conservando un alto alcance.
- Estado de verificación: No verificado
- Tasa de interacción (ER): El promedio de interacción de la audiencia es 2.55%. Durante las primeras 24 horas tras publicar, el contenido suele obtener 0.92% de reacciones respecto al total de suscriptores.
- Alcance de las publicaciones: Cada publicación recibe en promedio 1 332 visualizaciones. En el primer día suele acumular 479 visualizaciones.
- Reacciones e interacción: La audiencia responde de forma activa: el promedio de reacciones por publicación es 3.
- Intereses temáticos: El contenido se centra en temas clave como sql, row, |--, dataset, visualization.
📝 Descripción y política de contenido
El autor describe el recurso como un espacio para expresar opiniones subjetivas:
“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”
Gracias a la alta frecuencia de actualizaciones (últimos datos recibidos el 12 junio, 2026), el canal mantiene la vigencia y un amplio alcance. La analítica demuestra que la audiencia interactúa activamente con el contenido, lo que lo convierte en un punto de referencia dentro de la categoría Educación.
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;
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