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Data Analyst Interview Resources

Data Analyst Interview Resources

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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

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📈 Аналітичний огляд Telegram-каналу Data Analyst Interview Resources

Канал Data Analyst Interview Resources (@dataanalystinterview) у мовному сегменті Англійська є активним учасником. На даний момент спільнота об'єднує 52 626 підписників, посідаючи 3 243 місце в категорії Освіта та 6 755 місце у регіоні Індія.

📊 Показники аудиторії та динаміка

З моменту свого створення невідомо, проект продемонстрував стрімке зростання, зібравши аудиторію у 52 626 підписників.

За останніми даними від 26 серпня, 2026, канал демонструє стабільну активність. Хоча за останні 30 днів спостерігається зміна кількості учасників на 76, а за останні 24 години на 8, загальне охоплення залишається високим.

  • Статус верифікації: Не верифікований
  • Рівень залученості (ER): Середній показник залученості аудиторії становить 1.94%. Протягом перших 24 годин після публікації контент зазвичай збирає 0.83% реакцій від загальної кількості підписників.
  • Охоплення публікацій: В середньому кожен допис отримує 1 022 переглядів. Протягом першої доби публікація в середньому набирає 438 переглядів.
  • Реакції та взаємодія: Аудиторія активно підтримує контент: середня кількість реакцій на один пост – 2.
  • Тематичні інтереси: Контент зосереджений навколо ключових тем, таких як sql, row, |--, dataset, visualization.

📝 Опис та контентна політика

Автор описує ресурс як майданчик для висловлення суб'єктивної думки:
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

Завдяки високій частоті оновлень (останні дані отримано 27 серпня, 2026), канал підтримує актуальність та високий рівень охоплення публікацій. Аналітика показує, що аудиторія активно взаємодіє з контентом, що робить його важливою точкою впливу в категорії Освіта.

52 626
Підписники
+824 години
-427 днів
+7630 день
Архів дописів
End to End Data Analytics Project Roadmap Step 1. Define the business problem Start with a clear question. Example: Why did sales drop last quarter? Decide success metric. Example: Revenue, growth rate. Step 2. Understand the data Identify data sources. Example: Sales table, customers table. Check rows, columns, data types. Spot missing values. Step 3. Clean the data Remove duplicates. Handle missing values. Fix data types. Standardize text. Tools: Excel or Power Query SQL for large datasets. Step 4. Explore the data Basic summaries. Trends over time. Top and bottom performers. Examples: Monthly sales trend, top 10 products, region-wise revenue. Step 5. Analyze and find insights Compare periods. Segment data. Identify drivers. Examples: Sales drop in one region, high churn in one customer segment. Step 6. Create visuals and dashboard KPIs on top. Trends in middle. Breakdown charts below. Tools: Power BI or Tableau. Step 7. Interpret results What changed? Why it changed? Business impact. Step 8. Give recommendations Actionable steps. Example: Increase ads in high margin regions. Step 9. Validate and iterate Cross-check numbers. Ask stakeholder questions. Step 10. Present clearly One-page summary. Simple language. Focus on impact. Sample project ideas • Sales performance analysis. • Customer churn analysis. • Marketing campaign analysis. • HR attrition dashboard. Mini task • Choose one project idea. • Write the business question. • List 3 metrics you will track. Example: For Sales Performance Analysis Business Question: Why did sales drop last quarter? Metrics: 1. Revenue growth rate 2. Sales target achievement (%) 3. Customer acquisition cost (CAC) Double Tap ♥️ For More

Every day you login... Work.. and logout. Days become months. Months become years. But nothing changes. Same role. Same work.
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Most Asked SQL Interview Questions at MAANG Companies🔥🔥 Preparing for an SQL Interview at MAANG Companies? Here are some crucial SQL Questions you should be ready to tackle: 1. How do you retrieve all columns from a table? SELECT * FROM table_name; 2. What SQL statement is used to filter records? SELECT * FROM table_name WHERE condition; The WHERE clause is used to filter records based on a specified condition. 3. How can you join multiple tables? Describe different types of JOINs. SELECT columns FROM table1 JOIN table2 ON table1.column = table2.column JOIN table3 ON table2.column = table3.column; Types of JOINs: 1. INNER JOIN: Returns records with matching values in both tables SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column; 2. LEFT JOIN: Returns all records from the left table & matched records from the right table. Unmatched records will have NULL values. SELECT * FROM table1 LEFT JOIN table2 ON table1.column = table2.column; 3. RIGHT JOIN: Returns all records from the right table & matched records from the left table. Unmatched records will have NULL values. SELECT * FROM table1 RIGHT JOIN table2 ON table1.column = table2.column; 4. FULL JOIN: Returns records when there is a match in either left or right table. Unmatched records will have NULL values. SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column; 4. What is the difference between WHERE & HAVING clauses? WHERE: Filters records before any groupings are made. SELECT * FROM table_name WHERE condition; HAVING: Filters records after groupings are made. SELECT column, COUNT(*) FROM table_name GROUP BY column HAVING COUNT(*) > value; 5. How do you calculate average, sum, minimum & maximum values in a column? Average: SELECT AVG(column_name) FROM table_name; Sum: SELECT SUM(column_name) FROM table_name; Minimum: SELECT MIN(column_name) FROM table_name; Maximum: SELECT MAX(column_name) FROM table_name; Here you can find essential SQL Interview Resources👇 https://t.me/mysqldata Like this post if you need more 👍❤️ Hope it helps :)

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SQL Interview Questions with Answers Part-1: ☑️ 1. What is SQL?     SQL (Structured Query Language) is a standardized programming language designed to manage and manipulate relational databases. It allows you to query, insert, update, and delete data, as well as create and modify schema objects like tables and views. 2. Differentiate between SQL and NoSQL databases.     SQL databases are relational, table-based, and use structured query language with fixed schemas, ideal for complex queries and transactions. NoSQL databases are non-relational, can be document, key-value, graph, or column-oriented, and are schema-flexible, designed for scalability and handling unstructured data. 3. What are the different types of SQL commands? ⦁ DDL (Data Definition Language): CREATE, ALTER, DROP (define and modify structure) ⦁ DML (Data Manipulation Language): SELECT, INSERT, UPDATE, DELETE (data operations) ⦁ DCL (Data Control Language): GRANT, REVOKE (permission control) ⦁ TCL (Transaction Control Language): COMMIT, ROLLBACK, SAVEPOINT (transaction management) 4. Explain the difference between WHERE and HAVING clauses.WHERE filters rows before grouping (used with SELECT, UPDATE). ⦁ HAVING filters groups after aggregation (used with GROUP BY), e.g., filtering aggregated results like sums or counts. 5. Write a SQL query to find the second highest salary in a table.     Using a subquery:
SELECT MAX(salary) FROM employees  
WHERE salary < (SELECT MAX(salary) FROM employees);
Or using DENSE_RANK():
SELECT salary FROM (  
  SELECT salary, DENSE_RANK() OVER (ORDER BY salary DESC) as rnk  
  FROM employees) t  
WHERE rnk = 2;
6. What is a JOIN? Explain different types of JOINs.     A JOIN combines rows from two or more tables based on a related column: ⦁ INNER JOIN: returns matching rows from both tables. ⦁ LEFT JOIN (LEFT OUTER JOIN): all rows from the left table, matched rows from right. ⦁ RIGHT JOIN (RIGHT OUTER JOIN): all rows from right table, matched rows from left. ⦁ FULL JOIN (FULL OUTER JOIN): all rows when there’s a match in either table. ⦁ CROSS JOIN: Cartesian product of both tables. 7. How do you optimize slow-performing SQL queries? ⦁ Use indexes appropriately to speed up lookups. ⦁ Avoid SELECT *; only select necessary columns. ⦁ Use joins carefully; filter early with WHERE clauses. ⦁ Analyze execution plans to identify bottlenecks. ⦁ Avoid unnecessary subqueries; use EXISTS or JOINs. ⦁ Limit result sets with pagination if dealing with large datasets. 8. What is a primary key? What is a foreign key? ⦁ Primary Key: A unique identifier for records in a table; it cannot be NULL. ⦁ Foreign Key: A field that creates a link between two tables by referring to the primary key in another table, enforcing referential integrity. 9. What are indexes? Explain clustered and non-clustered indexes. ⦁ Indexes speed up data retrieval by providing quick lookups. ⦁ Clustered Index: Sorts and stores the actual data rows in the table based on the key; a table can have only one clustered index. ⦁ Non-Clustered Index: Creates a separate structure that points to the data rows; tables can have multiple non-clustered indexes. 10. Write a SQL query to fetch the top 5 records from a table.      In SQL Server and PostgreSQL:
SELECT * FROM table_name  
ORDER BY some_column DESC  
LIMIT 5;  
In SQL Server (older syntax):
SELECT TOP 5 * FROM table_name  
ORDER BY some_column DESC;  
React ♥️ for Part 2

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🔥 Pandas Interview Q&A (Frequently Asked 🔥) 📊 Q1. What is Pandas and why is it used? 👉 Python library for data manipulation & analysis 👉 Provides powerful data structures like DataFrame & Series 👉 Used for cleaning, transforming, and analyzing data 📊 Q2. What is the difference between Series and DataFrame? 👉 Series → 1D labeled array (single column) 👉 DataFrame → 2D tabular structure (rows & columns) 👉 DataFrame is a collection of multiple Series 📊 Q3. How do you handle missing values in Pandas? 👉 isnull() / notnull() to detect missing values 👉 fillna() to replace missing data 👉 dropna() to remove missing records 📊 Q4. What is the difference between loc[] and iloc[]? 👉 loc[] → Label-based indexing 👉 iloc[] → Integer position-based indexing 👉 Use loc for named indexes, iloc for numeric positions 📊 Q5. What is groupby() in Pandas? 👉 Used for splitting data into groups 👉 Apply aggregation functions (sum, mean, count) 👉 Essential for data summarization 📊 Q6. What is the difference between merge() and concat()? 👉 merge() → SQL-like joins (inner, left, right, outer) 👉 concat() → Stacks data vertically or horizontally 👉 Use merge for relational data combining 📊 Q7. How do you filter data in Pandas? 👉 Use boolean conditions (df[df['col'] > value]) 👉 Multiple conditions using & and | 👉 Helps in extracting specific insights 📊 Q8. What is apply() function? 👉 Applies a function across rows or columns 👉 Used for custom transformations 👉 More flexible than built-in functions 🔥 React with ♥️ for more such questions

𝗔𝗜/𝗠𝗟 𝗖𝗲𝗿𝘁𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗣𝗿𝗼𝗴𝗿𝗮𝗺 𝗕𝘆 𝗩𝗶𝘀𝗵𝗹𝗲𝘀𝗮𝗻 𝗶-𝗛𝘂𝗯, 𝗜𝗜𝗧 𝗣𝗮𝘁𝗻𝗮 𝗖𝗲𝗿𝘁𝗶𝗳𝗶𝗰𝗮𝘁
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🔥 Power BI Interview Q&A ( Frequently Asked 🔥) 📊 Q1. What is the difference between a calculated column and a measure? 👉 Calculated Column → Row-level, stored in memory 👉 Measure → Aggregated, calculated on the fly 👉 Use measures for performance & dynamic analysis 📊 Q2. What is a star schema and why is it important? 👉 Central fact table + surrounding dimension tables 👉 Improves performance & scalability 👉 Makes DAX simpler and more efficient 📊 Q3. What are filter context and row context in DAX? 👉 Row Context → Works at individual row level 👉 Filter Context → Applies filters across data 👉 Understanding both is key to writing correct DAX 📊 Q4. What is the use of CALCULATE() in Power BI? 👉 Modifies filter context 👉 Used for advanced calculations 👉 Core function for most complex DAX logic 📊 Q5. How do you handle missing or null values in Power BI? 👉 Use Power Query (Replace / Fill options) 👉 Handle with DAX (COALESCE, IF) 👉 Ensure clean data before building visuals 🔥 React with ♥️ for more such questions

🔥 Top SQL Interview Questions with Answers 🎯 1️⃣ Find 2nd Highest Salary 📊 Table: employees id | name | salary 1 | Rahul | 50000 2 | Priya | 70000 3 | Amit | 60000 4 | Neha | 70000 ❓ Problem Statement: Find the second highest distinct salary from the employees table. ✅ Solution SELECT MAX(salary) FROM employees WHERE salary < ( SELECT MAX(salary) FROM employees ); 🎯 2️⃣ Find Nth Highest Salary 📊 Table: employees id | name | salary 1 | A | 100 2 | B | 200 3 | C | 300 4 | D | 200 ❓ Problem Statement: Write a query to find the 3rd highest salary. ✅ Solution SELECT salary FROM ( SELECT salary, DENSE_RANK() OVER(ORDER BY salary DESC) r FROM employees ) t WHERE r = 3; 🎯 3️⃣ Find Duplicate Records 📊 Table: employees id | name 1 | Rahul 2 | Amit 3 | Rahul 4 | Neha ❓ Problem Statement: Find all duplicate names in the employees table. ✅ Solution SELECT name, COUNT(*) FROM employees GROUP BY name HAVING COUNT(*) > 1; 🎯 4️⃣ Customers with No Orders 📊 Table: customers customer_id | name 1 | Rahul 2 | Priya 3 | Amit 📊 Table: orders order_id | customer_id 101 | 1 102 | 2 ❓ Problem Statement: Find customers who have not placed any orders. ✅ Solution SELECT c.name FROM customers c LEFT JOIN orders o ON c.customer_id = o.customer_id WHERE o.customer_id IS NULL; 🎯 5️⃣ Top 3 Salaries per Department 📊 Table: employees name | department | salary A | IT | 100 B | IT | 200 C | IT | 150 D | HR | 120 E | HR | 180 ❓ Problem Statement: Find the top 3 highest salaries in each department. ✅ Solution SELECT * FROM ( SELECT name, department, salary, ROW_NUMBER() OVER( PARTITION BY department ORDER BY salary DESC ) r FROM employees ) t WHERE r <= 3; 🎯 6️⃣ Running Total of Sales 📊 Table: sales date | sales 2024-01-01 | 100 2024-01-02 | 200 2024-01-03 | 300 ❓ Problem Statement: Calculate the running total of sales by date. ✅ Solution SELECT date, sales, SUM(sales) OVER(ORDER BY date) AS running_total FROM sales; 🎯 7️⃣ Employees Above Average Salary 📊 Table: employees name | salary A | 100 B | 200 C | 300 ❓ Problem Statement: Find employees earning more than the average salary. ✅ Solution SELECT name, salary FROM employees WHERE salary > ( SELECT AVG(salary) FROM employees ); 🎯 8️⃣ Department with Highest Total Salary 📊 Table: employees name | department | salary A | IT | 100 B | IT | 200 C | HR | 500 ❓ Problem Statement: Find the department with the highest total salary. ✅ Solution SELECT department, SUM(salary) AS total_salary FROM employees GROUP BY department ORDER BY total_salary DESC LIMIT 1; 🎯 9️⃣ Customers Who Placed Orders 📊 Tables: Same as Q4 ❓ Problem Statement: Find customers who have placed at least one order. ✅ Solution SELECT name FROM customers c WHERE EXISTS ( SELECT 1 FROM orders o WHERE c.customer_id = o.customer_id ); 🎯 🔟 Remove Duplicate Records 📊 Table: employees id | name 1 | Rahul 2 | Rahul 3 | Amit ❓ Problem Statement: Delete duplicate records but keep one unique record. ✅ Solution DELETE FROM employees WHERE id NOT IN ( SELECT MIN(id) FROM employees GROUP BY name ); 🚀 Pro Tip: 👉 In interviews: First explain logic Then write query Then optimize Double Tap ♥️ For More

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Data Analytics Interview Questions with Answers Part-1: 📱 1. What is the difference between data analysis and data analytics?Data analysis involves inspecting, cleaning, and modeling data to discover useful information and patterns for decision-making. ⦁ Data analytics is a broader process that includes data collection, transformation, analysis, and interpretation, often involving predictive and prescriptive techniques to drive business strategies. 2. Explain the data cleaning process you follow. ⦁ Identify missing, inconsistent, or corrupt data. ⦁ Handle missing data by imputation (mean, median, mode) or removal if appropriate. ⦁ Standardize formats (dates, strings). ⦁ Remove duplicates. ⦁ Detect and treat outliers. ⦁ Validate cleaned data against known business rules. 3. How do you handle missing or duplicate data?Missing data: Identify patterns; if random, impute using statistical methods or predictive modeling; else consider domain knowledge before removal. ⦁ Duplicate data: Detect with key fields; remove exact duplicates or merge fuzzy duplicates based on context. 4. What is a primary key in a database?  A primary key uniquely identifies each record in a table, ensuring entity integrity and enabling relationships between tables via foreign keys. 5. Write a SQL query to find the second highest salary in a table.
SELECT MAX(salary) 
FROM employees 
WHERE salary < (SELECT MAX(salary) FROM employees);
6. Explain INNER JOIN vs LEFT JOIN with examples.INNER JOIN: Returns only matching rows between two tables. ⦁ LEFT JOIN: Returns all rows from the left table, plus matching rows from the right; if no match, right columns are NULL. Example:
SELECT * FROM A INNER JOIN B ON A.id = B.id;
SELECT * FROM A LEFT JOIN B ON A.id = B.id;
7. What are outliers? How do you detect and treat them?Outliers are data points significantly different from others that can skew analysis. ⦁ Detect with boxplots, z-score (>3), or IQR method (values outside 1.5*IQR). ⦁ Treat by investigating causes, correcting errors, transforming data, or removing if they’re noise. 8. Describe what a pivot table is and how you use it.  A pivot table is a data summarization tool that groups, aggregates (sum, average), and displays data cross-categorically. Used in Excel and BI tools for quick insights and reporting. 9. How do you validate a data model’s performance? ⦁ Use relevant metrics (accuracy, precision, recall for classification; RMSE, MAE for regression). ⦁ Perform cross-validation to check generalizability. ⦁ Test on holdout or unseen data sets. 10. What is hypothesis testing? Explain t-test and z-test. ⦁ Hypothesis testing assesses if sample data supports a claim about a population. ⦁ t-test: Used when sample size is small and population variance is unknown, often comparing means. ⦁ z-test: Used for large samples with known variance to test population parameters. React ♥️ for Part-2

A-Z Data Science Roadmap (Beginner to Job Ready) 📊🧠 1️⃣ Learn Python Basics • Variables, data types, loops, functions • Libraries: NumPy, Pandas 2️⃣ Data Cleaning Manipulation • Handling missing values, duplicates • Data wrangling with Pandas • GroupBy, merge, pivot tables 3️⃣ Data Visualization • Matplotlib, Seaborn • Plotly for interactive charts • Visualizing distributions, trends, relationships 4️⃣ Math for Data Science • Statistics (mean, median, std, distributions) • Probability basics • Linear algebra (vectors, matrices) • Calculus (for ML intuition) 5️⃣ SQL for Data Analysis • SELECT, JOIN, GROUP BY, subqueries • Window functions • Real-world queries on large datasets 6️⃣ Exploratory Data Analysis (EDA) • Univariate multivariate analysis • Outlier detection • Correlation heatmaps 7️⃣ Machine Learning (ML) • Supervised vs Unsupervised • Regression, classification, clustering • Train-test split, cross-validation • Overfitting, regularization 8️⃣ ML with scikit-learn • Linear logistic regression • Decision trees, random forest, SVM • K-means clustering • Model evaluation metrics (accuracy, RMSE, F1) 9️⃣ Deep Learning (Basics) • Neural networks, activation functions • TensorFlow / PyTorch • MNIST digit classifier 🔟 Projects to Build • Titanic survival prediction • House price prediction • Customer segmentation • Sentiment analysis • Dashboard + ML combo 1️⃣1️⃣ Tools to Learn • Jupyter Notebook • Git GitHub • Google Colab • VS Code 1️⃣2️⃣ Model Deployment • Streamlit, Flask APIs • Deploy on Render, Heroku or Hugging Face Spaces 1️⃣3️⃣ Communication Skills • Present findings clearly • Build dashboards or reports • Use storytelling with data 1️⃣4️⃣ Portfolio Resume • Upload projects on GitHub • Write blogs on Medium/Kaggle • Create a LinkedIn-optimized profile 💡 Pro Tip: Learn by building real projects and explaining them simply! 💬 Tap ❤️ for more!

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7 Misconceptions About Data Analytics (and What’s Actually True): 📊🚀 ❌ You need to be a math or statistics genius ✅ Basic math + logical thinking is enough. Most real-world analytics is about understanding data, not complex formulas. ❌ You must learn every tool before applying for jobs ✅ Start with core tools (Excel, SQL, one BI tool). Master fundamentals — tools can be learned on the job. ❌ Data analytics is only about numbers ✅ It’s about storytelling with data — explaining insights clearly to non-technical stakeholders. ❌ You need coding skills like a software developer ✅ Not required. SQL + basic Python/R is enough for most analyst roles. Deep coding is optional, not mandatory. ❌ Analysts just make dashboards all day ✅ Dashboards are just one part. Real work includes data cleaning, business understanding, ad-hoc analysis, and decision support. ❌ You need huge datasets to be a “real” data analyst ✅ Even small datasets can provide powerful insights if the questions are right. ❌ Once you learn analytics, your learning is done ✅ Data analytics evolves constantly — new tools, business problems, and techniques mean continuous learning. 💬 Tap ❤️ if you agree

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🧠 SQL Interview Question (Detect Negative Account Balance) 📌 transactions(txn_id, txn_date, amount) (credit = +ve, debit = -ve) ❓ Ques : 👉 Find the first date when account balance becomes negative 👉 Return txn_date 🧩 How Interviewers Expect You to Think • Calculate running balance over time 💰 • Use cumulative sum • Track when balance drops below zero • Return first occurrence 💡 SQL Solution WITH balance_cte AS ( SELECT txn_date, SUM(amount) OVER ( ORDER BY txn_date ) AS running_balance FROM transactions ) SELECT txn_date FROM balance_cte WHERE running_balance < 0 ORDER BY txn_date LIMIT 1; 🔥 Why This Question Is Powerful • Tests cumulative sum (window function) 🧠 • Very common in fintech & transaction analysis • Checks real-world problem solving ability ❤️ React for more SQL interview questions 🚀

🔥 Top SQL Interview Questions with Answers 🎯 1️⃣ Find 2nd Highest Salary 📊 Table: employees id | name | salary 1 | Rahul | 50000 2 | Priya | 70000 3 | Amit | 60000 4 | Neha | 70000 ❓ Problem Statement: Find the second highest distinct salary from the employees table. ✅ Solution SELECT MAX(salary) FROM employees WHERE salary < ( SELECT MAX(salary) FROM employees ); 🎯 2️⃣ Find Nth Highest Salary 📊 Table: employees id | name | salary 1 | A | 100 2 | B | 200 3 | C | 300 4 | D | 200 ❓ Problem Statement: Write a query to find the 3rd highest salary. ✅ Solution SELECT salary FROM ( SELECT salary, DENSE_RANK() OVER(ORDER BY salary DESC) r FROM employees ) t WHERE r = 3; 🎯 3️⃣ Find Duplicate Records 📊 Table: employees id | name 1 | Rahul 2 | Amit 3 | Rahul 4 | Neha ❓ Problem Statement: Find all duplicate names in the employees table. ✅ Solution SELECT name, COUNT(*) FROM employees GROUP BY name HAVING COUNT(*) > 1; 🎯 4️⃣ Customers with No Orders 📊 Table: customers customer_id | name 1 | Rahul 2 | Priya 3 | Amit 📊 Table: orders order_id | customer_id 101 | 1 102 | 2 ❓ Problem Statement: Find customers who have not placed any orders. ✅ Solution SELECT c.name FROM customers c LEFT JOIN orders o ON c.customer_id = o.customer_id WHERE o.customer_id IS NULL; 🎯 5️⃣ Top 3 Salaries per Department 📊 Table: employees name | department | salary A | IT | 100 B | IT | 200 C | IT | 150 D | HR | 120 E | HR | 180 ❓ Problem Statement: Find the top 3 highest salaries in each department. ✅ Solution SELECT * FROM ( SELECT name, department, salary, ROW_NUMBER() OVER( PARTITION BY department ORDER BY salary DESC ) r FROM employees ) t WHERE r <= 3; 🎯 6️⃣ Running Total of Sales 📊 Table: sales date | sales 2024-01-01 | 100 2024-01-02 | 200 2024-01-03 | 300 ❓ Problem Statement: Calculate the running total of sales by date. ✅ Solution SELECT date, sales, SUM(sales) OVER(ORDER BY date) AS running_total FROM sales; 🎯 7️⃣ Employees Above Average Salary 📊 Table: employees name | salary A | 100 B | 200 C | 300 ❓ Problem Statement: Find employees earning more than the average salary. ✅ Solution SELECT name, salary FROM employees WHERE salary > ( SELECT AVG(salary) FROM employees ); 🎯 8️⃣ Department with Highest Total Salary 📊 Table: employees name | department | salary A | IT | 100 B | IT | 200 C | HR | 500 ❓ Problem Statement: Find the department with the highest total salary. ✅ Solution SELECT department, SUM(salary) AS total_salary FROM employees GROUP BY department ORDER BY total_salary DESC LIMIT 1; 🎯 9️⃣ Customers Who Placed Orders 📊 Tables: Same as Q4 ❓ Problem Statement: Find customers who have placed at least one order. ✅ Solution SELECT name FROM customers c WHERE EXISTS ( SELECT 1 FROM orders o WHERE c.customer_id = o.customer_id ); 🎯 🔟 Remove Duplicate Records 📊 Table: employees id | name 1 | Rahul 2 | Rahul 3 | Amit ❓ Problem Statement: Delete duplicate records but keep one unique record. ✅ Solution DELETE FROM employees WHERE id NOT IN ( SELECT MIN(id) FROM employees GROUP BY name ); 🚀 Pro Tip: 👉 In interviews: First explain logic Then write query Then optimize Double Tap ♥️ For More

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