Complete Syllabus for Data Analytics interview:
SQL:
1. Basic
- SELECT statements with WHERE, ORDER BY, GROUP BY, HAVING
- Basic JOINS (INNER, LEFT, RIGHT, FULL)
- Creating and using simple databases and tables
2. Intermediate
- Aggregate functions (COUNT, SUM, AVG, MAX, MIN)
- Subqueries and nested queries
- Common Table Expressions (WITH clause)
- CASE statements for conditional logic in queries
3. Advanced
- Advanced JOIN techniques (self-join, non-equi join)
- Window functions (OVER, PARTITION BY, ROW_NUMBER, RANK, DENSE_RANK, lead, lag)
- optimization with indexing
- Data manipulation (INSERT, UPDATE, DELETE)
Python:
1. Basic
- Syntax, variables, data types (integers, floats, strings, booleans)
- Control structures (if-else, for and while loops)
- Basic data structures (lists, dictionaries, sets, tuples)
- Functions, lambda functions, error handling (try-except)
- Modules and packages
2. Pandas & Numpy
- Creating and manipulating DataFrames and Series
- Indexing, selecting, and filtering data
- Handling missing data (fillna, dropna)
- Data aggregation with groupby, summarizing data
- Merging, joining, and concatenating datasets
3. Basic Visualization
- Basic plotting with Matplotlib (line plots, bar plots, histograms)
- Visualization with Seaborn (scatter plots, box plots, pair plots)
- Customizing plots (sizes, labels, legends, color palettes)
- Introduction to interactive visualizations (e.g., Plotly)
Excel:
1. Basic
- Cell operations, basic formulas (SUMIFS, COUNTIFS, AVERAGEIFS, IF, AND, OR, NOT & Nested Functions etc.)
- Introduction to charts and basic data visualization
- Data sorting and filtering
- Conditional formatting
2. Intermediate
- Advanced formulas (V/XLOOKUP, INDEX-MATCH, nested IF)
- PivotTables and PivotCharts for summarizing data
- Data validation tools
- What-if analysis tools (Data Tables, Goal Seek)
3. Advanced
- Array formulas and advanced functions
- Data Model & Power Pivot
- Advanced Filter
- Slicers and Timelines in Pivot Tables
- Dynamic charts and interactive dashboards
Power BI:
1. Data Modeling
- Importing data from various sources
- Creating and managing relationships between different datasets
- Data modeling basics (star schema, snowflake schema)
2. Data Transformation
- Using Power Query for data cleaning and transformation
- Advanced data shaping techniques
- Calculated columns and measures using DAX
3. Data Visualization and Reporting
- Creating interactive reports and dashboards
- Visualizations (bar, line, pie charts, maps)
- Publishing and sharing reports, scheduling data refreshes
Statistics Fundamentals:
Mean, Median, Mode, Standard Deviation, Variance, Probability Distributions, Hypothesis Testing, P-values, Confidence Intervals, Correlation, Simple Linear Regression, Normal Distribution, Binomial Distribution, Poisson Distribution.
SQL:
1. Basic
- SELECT statements with WHERE, ORDER BY, GROUP BY, HAVING
- Basic JOINS (INNER, LEFT, RIGHT, FULL)
- Creating and using simple databases and tables
2. Intermediate
- Aggregate functions (COUNT, SUM, AVG, MAX, MIN)
- Subqueries and nested queries
- Common Table Expressions (WITH clause)
- CASE statements for conditional logic in queries
3. Advanced
- Advanced JOIN techniques (self-join, non-equi join)
- Window functions (OVER, PARTITION BY, ROW_NUMBER, RANK, DENSE_RANK, lead, lag)
- optimization with indexing
- Data manipulation (INSERT, UPDATE, DELETE)
Python:
1. Basic
- Syntax, variables, data types (integers, floats, strings, booleans)
- Control structures (if-else, for and while loops)
- Basic data structures (lists, dictionaries, sets, tuples)
- Functions, lambda functions, error handling (try-except)
- Modules and packages
2. Pandas & Numpy
- Creating and manipulating DataFrames and Series
- Indexing, selecting, and filtering data
- Handling missing data (fillna, dropna)
- Data aggregation with groupby, summarizing data
- Merging, joining, and concatenating datasets
3. Basic Visualization
- Basic plotting with Matplotlib (line plots, bar plots, histograms)
- Visualization with Seaborn (scatter plots, box plots, pair plots)
- Customizing plots (sizes, labels, legends, color palettes)
- Introduction to interactive visualizations (e.g., Plotly)
Excel:
1. Basic
- Cell operations, basic formulas (SUMIFS, COUNTIFS, AVERAGEIFS, IF, AND, OR, NOT & Nested Functions etc.)
- Introduction to charts and basic data visualization
- Data sorting and filtering
- Conditional formatting
2. Intermediate
- Advanced formulas (V/XLOOKUP, INDEX-MATCH, nested IF)
- PivotTables and PivotCharts for summarizing data
- Data validation tools
- What-if analysis tools (Data Tables, Goal Seek)
3. Advanced
- Array formulas and advanced functions
- Data Model & Power Pivot
- Advanced Filter
- Slicers and Timelines in Pivot Tables
- Dynamic charts and interactive dashboards
Power BI:
1. Data Modeling
- Importing data from various sources
- Creating and managing relationships between different datasets
- Data modeling basics (star schema, snowflake schema)
2. Data Transformation
- Using Power Query for data cleaning and transformation
- Advanced data shaping techniques
- Calculated columns and measures using DAX
3. Data Visualization and Reporting
- Creating interactive reports and dashboards
- Visualizations (bar, line, pie charts, maps)
- Publishing and sharing reports, scheduling data refreshes
Statistics Fundamentals:
Mean, Median, Mode, Standard Deviation, Variance, Probability Distributions, Hypothesis Testing, P-values, Confidence Intervals, Correlation, Simple Linear Regression, Normal Distribution, Binomial Distribution, Poisson Distribution.
❤1
𝗔𝗰𝗲 𝗬𝗼𝘂𝗿 𝗗𝗮𝘁𝗮 𝗔𝗻𝗮𝗹𝘆𝘀𝘁 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄 𝘄𝗶𝘁𝗵 𝗧𝗵𝗲𝘀𝗲 𝗠𝘂𝘀𝘁-𝗞𝗻𝗼𝘄 𝗤𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝘀! 🔥
Are you preparing for a 𝗗𝗮𝘁𝗮 𝗔𝗻𝗮𝗹𝘆𝘀𝘁 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄? Hiring managers don’t just want to hear your answers—they want to know if you truly understand data.
Here are 𝗳𝗿𝗲𝗾𝘂𝗲𝗻𝘁𝗹𝘆 𝗮𝘀𝗸𝗲𝗱 𝗾𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝘀 (and what they really mean):
📌 "𝗧𝗲𝗹𝗹 𝗺𝗲 𝗮𝗯𝗼𝘂𝘁 𝘆𝗼𝘂𝗿𝘀𝗲𝗹𝗳."
🔍 What they’re really asking: Are you relevant for this role?
✅ Keep it concise—highlight your experience, tools (SQL, Power BI, etc.), and a key impact you made.
📌 "𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗵𝗮𝗻𝗱𝗹𝗲 𝗺𝗲𝘀𝘀𝘆 𝗱𝗮𝘁𝗮?"
🔍 What they’re really asking: Do you panic when you see missing values?
✅ Show your structured approach—identify issues, clean with Pandas/SQL, and document your process.
📌 "𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝗮 𝗱𝗮𝘁𝗮 𝗮𝗻𝗮𝗹𝘆𝘀𝗶𝘀 𝗽𝗿𝗼𝗷𝗲𝗰𝘁?"
🔍 What they’re really asking: Do you have a methodology, or do you just wing it?
✅ Use a structured approach: Define business needs → Clean & explore data → Generate insights → Present effectively.
📌 "𝗖𝗮𝗻 𝘆𝗼𝘂 𝗲𝘅𝗽𝗹𝗮𝗶𝗻 𝗮 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗰𝗼𝗻𝗰𝗲𝗽𝘁 𝘁𝗼 𝗮 𝗻𝗼𝗻-𝘁𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹
𝘀𝘁𝗮𝗸𝗲𝗵𝗼𝗹𝗱𝗲𝗿?"
🔍 What they’re really asking: Can you simplify data without oversimplifying?
✅ Use storytelling—focus on actionable insights rather than jargon.
📌 "𝗧𝗲𝗹𝗹 𝗺𝗲 𝗮𝗯𝗼𝘂𝘁 𝗮 𝘁𝗶𝗺𝗲 𝘆𝗼𝘂 𝗺𝗮𝗱𝗲 𝗮 𝗺𝗶𝘀𝘁𝗮𝗸𝗲."
🔍 What they’re really asking: Can you learn from failure?
✅ Own your mistake, explain how you fixed it, and share what you do differently now.
💡 𝗣𝗿𝗼 𝗧𝗶𝗽: The best candidates don’t just answer questions—they tell stories that demonstrate problem-solving, clarity, and impact.
🔄 Save this for later & share with someone preparing for interviews!
Are you preparing for a 𝗗𝗮𝘁𝗮 𝗔𝗻𝗮𝗹𝘆𝘀𝘁 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄? Hiring managers don’t just want to hear your answers—they want to know if you truly understand data.
Here are 𝗳𝗿𝗲𝗾𝘂𝗲𝗻𝘁𝗹𝘆 𝗮𝘀𝗸𝗲𝗱 𝗾𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝘀 (and what they really mean):
📌 "𝗧𝗲𝗹𝗹 𝗺𝗲 𝗮𝗯𝗼𝘂𝘁 𝘆𝗼𝘂𝗿𝘀𝗲𝗹𝗳."
🔍 What they’re really asking: Are you relevant for this role?
✅ Keep it concise—highlight your experience, tools (SQL, Power BI, etc.), and a key impact you made.
📌 "𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗵𝗮𝗻𝗱𝗹𝗲 𝗺𝗲𝘀𝘀𝘆 𝗱𝗮𝘁𝗮?"
🔍 What they’re really asking: Do you panic when you see missing values?
✅ Show your structured approach—identify issues, clean with Pandas/SQL, and document your process.
📌 "𝗛𝗼𝘄 𝗱𝗼 𝘆𝗼𝘂 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝗮 𝗱𝗮𝘁𝗮 𝗮𝗻𝗮𝗹𝘆𝘀𝗶𝘀 𝗽𝗿𝗼𝗷𝗲𝗰𝘁?"
🔍 What they’re really asking: Do you have a methodology, or do you just wing it?
✅ Use a structured approach: Define business needs → Clean & explore data → Generate insights → Present effectively.
📌 "𝗖𝗮𝗻 𝘆𝗼𝘂 𝗲𝘅𝗽𝗹𝗮𝗶𝗻 𝗮 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗰𝗼𝗻𝗰𝗲𝗽𝘁 𝘁𝗼 𝗮 𝗻𝗼𝗻-𝘁𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹
𝘀𝘁𝗮𝗸𝗲𝗵𝗼𝗹𝗱𝗲𝗿?"
🔍 What they’re really asking: Can you simplify data without oversimplifying?
✅ Use storytelling—focus on actionable insights rather than jargon.
📌 "𝗧𝗲𝗹𝗹 𝗺𝗲 𝗮𝗯𝗼𝘂𝘁 𝗮 𝘁𝗶𝗺𝗲 𝘆𝗼𝘂 𝗺𝗮𝗱𝗲 𝗮 𝗺𝗶𝘀𝘁𝗮𝗸𝗲."
🔍 What they’re really asking: Can you learn from failure?
✅ Own your mistake, explain how you fixed it, and share what you do differently now.
💡 𝗣𝗿𝗼 𝗧𝗶𝗽: The best candidates don’t just answer questions—they tell stories that demonstrate problem-solving, clarity, and impact.
🔄 Save this for later & share with someone preparing for interviews!
❤2
Questions & Answers for Data Analyst Interview
Question 1: Describe a time when you used data analysis to solve a business problem.
Ideal answer: This is your opportunity to showcase your data analysis skills in a real-world context. Be specific and provide examples of your work. For example, you could talk about a time when you used data analysis to identify customer churn, improve marketing campaigns, or optimize product development.
Question 2: What are some of the challenges you have faced in previous data analysis projects, and how did you overcome them?
Ideal answer: This question is designed to assess your problem-solving skills and your ability to learn from your experiences. Be honest and upfront about the challenges you have faced, but also focus on how you overcame them. For example, you could talk about a time when you had to deal with a large and messy dataset, or a time when you had to work with a tight deadline.
Question 3: How do you handle missing values in a dataset?
Ideal answer: Missing values are a common problem in data analysis, so it is important to know how to handle them properly. There are a variety of different methods that you can use, depending on the specific situation. For example, you could delete the rows with missing values, impute the missing values using a statistical method, or assign a default value to the missing values.
Question 4: How do you identify and remove outliers?
Ideal answer: Outliers are data points that are significantly different from the rest of the data. They can be caused by data errors or by natural variation in the data. It is important to identify and remove outliers before performing data analysis, as they can skew the results. There are a variety of different methods that you can use to identify outliers, such as the interquartile range (IQR) method or the standard deviation method.
Question 5: How do you interpret and communicate the results of your data analysis to non-technical audiences?
Ideal answer: It is important to be able to communicate your data analysis findings to both technical and non-technical audiences. When communicating to non-technical audiences, it is important to avoid using jargon and to focus on the key takeaways from your analysis. You can use data visualization tools to help you communicate your findings in a clear and concise way.
In addition to providing specific examples and answers to the questions, it is also important to be enthusiastic and demonstrate your passion for data analysis. Show the interviewer that you are excited about the opportunity to use your skills to solve real-world problems.
Question 1: Describe a time when you used data analysis to solve a business problem.
Ideal answer: This is your opportunity to showcase your data analysis skills in a real-world context. Be specific and provide examples of your work. For example, you could talk about a time when you used data analysis to identify customer churn, improve marketing campaigns, or optimize product development.
Question 2: What are some of the challenges you have faced in previous data analysis projects, and how did you overcome them?
Ideal answer: This question is designed to assess your problem-solving skills and your ability to learn from your experiences. Be honest and upfront about the challenges you have faced, but also focus on how you overcame them. For example, you could talk about a time when you had to deal with a large and messy dataset, or a time when you had to work with a tight deadline.
Question 3: How do you handle missing values in a dataset?
Ideal answer: Missing values are a common problem in data analysis, so it is important to know how to handle them properly. There are a variety of different methods that you can use, depending on the specific situation. For example, you could delete the rows with missing values, impute the missing values using a statistical method, or assign a default value to the missing values.
Question 4: How do you identify and remove outliers?
Ideal answer: Outliers are data points that are significantly different from the rest of the data. They can be caused by data errors or by natural variation in the data. It is important to identify and remove outliers before performing data analysis, as they can skew the results. There are a variety of different methods that you can use to identify outliers, such as the interquartile range (IQR) method or the standard deviation method.
Question 5: How do you interpret and communicate the results of your data analysis to non-technical audiences?
Ideal answer: It is important to be able to communicate your data analysis findings to both technical and non-technical audiences. When communicating to non-technical audiences, it is important to avoid using jargon and to focus on the key takeaways from your analysis. You can use data visualization tools to help you communicate your findings in a clear and concise way.
In addition to providing specific examples and answers to the questions, it is also important to be enthusiastic and demonstrate your passion for data analysis. Show the interviewer that you are excited about the opportunity to use your skills to solve real-world problems.
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Essential Topics to Master Data Analytics Interviews: 🚀
SQL:
1. Foundations
- SELECT statements with WHERE, ORDER BY, GROUP BY, HAVING
- Basic JOINS (INNER, LEFT, RIGHT, FULL)
- Navigate through simple databases and tables
2. Intermediate SQL
- Utilize Aggregate functions (COUNT, SUM, AVG, MAX, MIN)
- Embrace Subqueries and nested queries
- Master Common Table Expressions (WITH clause)
- Implement CASE statements for logical queries
3. Advanced SQL
- Explore Advanced JOIN techniques (self-join, non-equi join)
- Dive into Window functions (OVER, PARTITION BY, ROW_NUMBER, RANK, DENSE_RANK, lead, lag)
- Optimize queries with indexing
- Execute Data manipulation (INSERT, UPDATE, DELETE)
Python:
1. Python Basics
- Grasp Syntax, variables, and data types
- Command Control structures (if-else, for and while loops)
- Understand Basic data structures (lists, dictionaries, sets, tuples)
- Master Functions, lambda functions, and error handling (try-except)
- Explore Modules and packages
2. Pandas & Numpy
- Create and manipulate DataFrames and Series
- Perfect Indexing, selecting, and filtering data
- Handle missing data (fillna, dropna)
- Aggregate data with groupby, summarizing data
- Merge, join, and concatenate datasets
3. Data Visualization with Python
- Plot with Matplotlib (line plots, bar plots, histograms)
- Visualize with Seaborn (scatter plots, box plots, pair plots)
- Customize plots (sizes, labels, legends, color palettes)
- Introduction to interactive visualizations (e.g., Plotly)
Excel:
1. Excel Essentials
- Conduct Cell operations, basic formulas (SUMIFS, COUNTIFS, AVERAGEIFS, IF, AND, OR, NOT & Nested Functions etc.)
- Dive into charts and basic data visualization
- Sort and filter data, use Conditional formatting
2. Intermediate Excel
- Master Advanced formulas (V/XLOOKUP, INDEX-MATCH, nested IF)
- Leverage PivotTables and PivotCharts for summarizing data
- Utilize data validation tools
- Employ What-if analysis tools (Data Tables, Goal Seek)
3. Advanced Excel
- Harness Array formulas and advanced functions
- Dive into Data Model & Power Pivot
- Explore Advanced Filter, Slicers, and Timelines in Pivot Tables
- Create dynamic charts and interactive dashboards
Power BI:
1. Data Modeling in Power BI
- Import data from various sources
- Establish and manage relationships between datasets
- Grasp Data modeling basics (star schema, snowflake schema)
2. Data Transformation in Power BI
- Use Power Query for data cleaning and transformation
- Apply advanced data shaping techniques
- Create Calculated columns and measures using DAX
3. Data Visualization and Reporting in Power BI
- Craft interactive reports and dashboards
- Utilize Visualizations (bar, line, pie charts, maps)
- Publish and share reports, schedule data refreshes
Statistics Fundamentals:
- Mean, Median, Mode
- Standard Deviation, Variance
- Probability Distributions, Hypothesis Testing
- P-values, Confidence Intervals
- Correlation, Simple Linear Regression
- Normal Distribution, Binomial Distribution, Poisson Distribution.
Show some ❤️ if you're ready to elevate your data analytics journey! 📊
ENJOY LEARNING 👍👍
SQL:
1. Foundations
- SELECT statements with WHERE, ORDER BY, GROUP BY, HAVING
- Basic JOINS (INNER, LEFT, RIGHT, FULL)
- Navigate through simple databases and tables
2. Intermediate SQL
- Utilize Aggregate functions (COUNT, SUM, AVG, MAX, MIN)
- Embrace Subqueries and nested queries
- Master Common Table Expressions (WITH clause)
- Implement CASE statements for logical queries
3. Advanced SQL
- Explore Advanced JOIN techniques (self-join, non-equi join)
- Dive into Window functions (OVER, PARTITION BY, ROW_NUMBER, RANK, DENSE_RANK, lead, lag)
- Optimize queries with indexing
- Execute Data manipulation (INSERT, UPDATE, DELETE)
Python:
1. Python Basics
- Grasp Syntax, variables, and data types
- Command Control structures (if-else, for and while loops)
- Understand Basic data structures (lists, dictionaries, sets, tuples)
- Master Functions, lambda functions, and error handling (try-except)
- Explore Modules and packages
2. Pandas & Numpy
- Create and manipulate DataFrames and Series
- Perfect Indexing, selecting, and filtering data
- Handle missing data (fillna, dropna)
- Aggregate data with groupby, summarizing data
- Merge, join, and concatenate datasets
3. Data Visualization with Python
- Plot with Matplotlib (line plots, bar plots, histograms)
- Visualize with Seaborn (scatter plots, box plots, pair plots)
- Customize plots (sizes, labels, legends, color palettes)
- Introduction to interactive visualizations (e.g., Plotly)
Excel:
1. Excel Essentials
- Conduct Cell operations, basic formulas (SUMIFS, COUNTIFS, AVERAGEIFS, IF, AND, OR, NOT & Nested Functions etc.)
- Dive into charts and basic data visualization
- Sort and filter data, use Conditional formatting
2. Intermediate Excel
- Master Advanced formulas (V/XLOOKUP, INDEX-MATCH, nested IF)
- Leverage PivotTables and PivotCharts for summarizing data
- Utilize data validation tools
- Employ What-if analysis tools (Data Tables, Goal Seek)
3. Advanced Excel
- Harness Array formulas and advanced functions
- Dive into Data Model & Power Pivot
- Explore Advanced Filter, Slicers, and Timelines in Pivot Tables
- Create dynamic charts and interactive dashboards
Power BI:
1. Data Modeling in Power BI
- Import data from various sources
- Establish and manage relationships between datasets
- Grasp Data modeling basics (star schema, snowflake schema)
2. Data Transformation in Power BI
- Use Power Query for data cleaning and transformation
- Apply advanced data shaping techniques
- Create Calculated columns and measures using DAX
3. Data Visualization and Reporting in Power BI
- Craft interactive reports and dashboards
- Utilize Visualizations (bar, line, pie charts, maps)
- Publish and share reports, schedule data refreshes
Statistics Fundamentals:
- Mean, Median, Mode
- Standard Deviation, Variance
- Probability Distributions, Hypothesis Testing
- P-values, Confidence Intervals
- Correlation, Simple Linear Regression
- Normal Distribution, Binomial Distribution, Poisson Distribution.
Show some ❤️ if you're ready to elevate your data analytics journey! 📊
ENJOY LEARNING 👍👍
❤2
TOP 10 SQL Concepts for Job Interview
1. Aggregate Functions (SUM/AVG)
2. Group By and Order By
3. JOINs (Inner/Left/Right)
4. Union and Union All
5. Date and Time processing
6. String processing
7. Window Functions (Partition by)
8. Subquery
9. View and Index
10. Common Table Expression (CTE)
TOP 10 Statistics Concepts for Job Interview
1. Sampling
2. Experiments (A/B tests)
3. Denoscriptive Statistics
4. p-value
5. Probability Distributions
6. t-test
7. ANOVA
8. Correlation
9. Linear Regression
10. Logistics Regression
TOP 10 Python Concepts for Job Interview
1. Reading data from file/table
2. Writing data to file/table
3. Data Types
4. Function
5. Data Preprocessing (numpy/pandas)
6. Data Visualisation (Matplotlib/seaborn/bokeh)
7. Machine Learning (sklearn)
8. Deep Learning (Tensorflow/Keras/PyTorch)
9. Distributed Processing (PySpark)
10. Functional and Object Oriented Programming
1. Aggregate Functions (SUM/AVG)
2. Group By and Order By
3. JOINs (Inner/Left/Right)
4. Union and Union All
5. Date and Time processing
6. String processing
7. Window Functions (Partition by)
8. Subquery
9. View and Index
10. Common Table Expression (CTE)
TOP 10 Statistics Concepts for Job Interview
1. Sampling
2. Experiments (A/B tests)
3. Denoscriptive Statistics
4. p-value
5. Probability Distributions
6. t-test
7. ANOVA
8. Correlation
9. Linear Regression
10. Logistics Regression
TOP 10 Python Concepts for Job Interview
1. Reading data from file/table
2. Writing data to file/table
3. Data Types
4. Function
5. Data Preprocessing (numpy/pandas)
6. Data Visualisation (Matplotlib/seaborn/bokeh)
7. Machine Learning (sklearn)
8. Deep Learning (Tensorflow/Keras/PyTorch)
9. Distributed Processing (PySpark)
10. Functional and Object Oriented Programming
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10 Data Analyst Interview Questions You Should Be Ready For (2025)
✅ Explain the difference between INNER JOIN and LEFT JOIN.
✅ What are window functions in SQL? Give an example.
✅ How do you handle missing or duplicate data in a dataset?
✅ Describe a situation where you derived insights that influenced a business decision.
✅ What’s the difference between correlation and causation?
✅ How would you optimize a slow SQL query?
✅ Explain the use of GROUP BY and HAVING in SQL.
✅ How do you choose the right chart for a dataset?
✅ What’s the difference between a dashboard and a report?
✅ Which libraries in Python do you use for data cleaning and analysis?
Like for the detailed answers for above questions ❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
✅ Explain the difference between INNER JOIN and LEFT JOIN.
✅ What are window functions in SQL? Give an example.
✅ How do you handle missing or duplicate data in a dataset?
✅ Describe a situation where you derived insights that influenced a business decision.
✅ What’s the difference between correlation and causation?
✅ How would you optimize a slow SQL query?
✅ Explain the use of GROUP BY and HAVING in SQL.
✅ How do you choose the right chart for a dataset?
✅ What’s the difference between a dashboard and a report?
✅ Which libraries in Python do you use for data cleaning and analysis?
Like for the detailed answers for above questions ❤️
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Hey guys,
Today, I’m covering some Excel interview questions that often pop up in data analyst roles 👇👇
1. What are the most common functions used in Excel for data analysis?
- SUM(): Adds up values in a range.
- AVERAGE(): Finds the mean of a range of numbers.
- VLOOKUP() / XLOOKUP(): Searches for a value in a table and returns a related value.
- INDEX-MATCH: A more flexible alternative to VLOOKUP, allowing lookups in any direction.
- IF(): Performs logical tests and returns one value if TRUE, another if FALSE.
- COUNTIF(): Counts the number of cells that meet a specific condition.
- PivotTables: For summarizing, analyzing, and exploring large datasets.
2. What is the difference between VLOOKUP and XLOOKUP?
- VLOOKUP is an older function used to find data in a vertical column and return a value from another column to the right.
Example:
- XLOOKUP is more powerful, offering the flexibility to search both vertically and horizontally, and it doesn’t require the lookup value to be in the first column.
Example:
Tip: Explain the limitations of VLOOKUP (like not being able to search left or needing sorted data for approximate matches) and how XLOOKUP overcomes them.
3. How do you create a PivotTable in Excel, and why is it useful?
A PivotTable allows you to summarize large amounts of data quickly. Here’s how to create one:
1. Select your data.
2. Go to the Insert tab and click on PivotTable.
3. Choose where to place the PivotTable.
4. Drag and drop fields into the Rows, Columns, Values, and Filters sections.
4. What is conditional formatting, and how do you use it?
Conditional formatting is used to change the appearance of cells based on their content. It helps highlight trends, patterns, and outliers.
For example, to highlight cells greater than 1000:
1. Select the range of cells.
2. Go to the Home tab, click on Conditional Formatting.
3. Choose Highlight Cell Rules > Greater Than and enter 1000.
4. Choose a format (e.g., cell color) to apply.
5. How do you handle large datasets in Excel without slowing it down?
Here are some strategies to improve efficiency:
- Turn off automatic calculations: Use manual recalculation to prevent Excel from recalculating formulas every time you make a change.
- Use fewer volatile functions: Functions like NOW(), TODAY(), and INDIRECT() recalculate every time a change is made.
- Use tables instead of ranges: Structured references in tables are more efficient.
- Split large datasets: If feasible, split your data across multiple sheets or workbooks.
- Remove unnecessary formatting: Too much formatting can bloat file size and slow down processing.
6. How do you use Excel for data cleaning?
Data cleaning is one of the first and most important steps in data analysis, and Excel provides multiple ways to do this:
- Remove duplicates: Easily eliminate duplicate entries.
- Text to Columns: Split data in one column into multiple columns (e.g., splitting full names into first and last names).
- TRIM(): Remove extra spaces from text.
- FIND() and SUBSTITUTE(): For locating and replacing specific characters or substrings.
7. What are some advanced Excel functions you’ve used for data analysis?
Aside from the basics, some advanced Excel functions you might mention include:
- ARRAYFORMULA(): Allows multiple calculations to be performed at once.
- OFFSET(): Returns a range that is offset from a starting point.
- FORECAST(): Predicts future values based on historical data.
- POWER QUERY: For data extraction, transformation, and loading (ETL) tasks.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://news.1rj.ru/str/DataSimplifier
Like for more Interview Resources ♥️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
Today, I’m covering some Excel interview questions that often pop up in data analyst roles 👇👇
1. What are the most common functions used in Excel for data analysis?
- SUM(): Adds up values in a range.
- AVERAGE(): Finds the mean of a range of numbers.
- VLOOKUP() / XLOOKUP(): Searches for a value in a table and returns a related value.
- INDEX-MATCH: A more flexible alternative to VLOOKUP, allowing lookups in any direction.
- IF(): Performs logical tests and returns one value if TRUE, another if FALSE.
- COUNTIF(): Counts the number of cells that meet a specific condition.
- PivotTables: For summarizing, analyzing, and exploring large datasets.
2. What is the difference between VLOOKUP and XLOOKUP?
- VLOOKUP is an older function used to find data in a vertical column and return a value from another column to the right.
Example:
=VLOOKUP("A2", B2:D10, 3, FALSE)
- XLOOKUP is more powerful, offering the flexibility to search both vertically and horizontally, and it doesn’t require the lookup value to be in the first column.
Example:
=XLOOKUP(A2, B2:B10, C2:C10)
Tip: Explain the limitations of VLOOKUP (like not being able to search left or needing sorted data for approximate matches) and how XLOOKUP overcomes them.
3. How do you create a PivotTable in Excel, and why is it useful?
A PivotTable allows you to summarize large amounts of data quickly. Here’s how to create one:
1. Select your data.
2. Go to the Insert tab and click on PivotTable.
3. Choose where to place the PivotTable.
4. Drag and drop fields into the Rows, Columns, Values, and Filters sections.
4. What is conditional formatting, and how do you use it?
Conditional formatting is used to change the appearance of cells based on their content. It helps highlight trends, patterns, and outliers.
For example, to highlight cells greater than 1000:
1. Select the range of cells.
2. Go to the Home tab, click on Conditional Formatting.
3. Choose Highlight Cell Rules > Greater Than and enter 1000.
4. Choose a format (e.g., cell color) to apply.
5. How do you handle large datasets in Excel without slowing it down?
Here are some strategies to improve efficiency:
- Turn off automatic calculations: Use manual recalculation to prevent Excel from recalculating formulas every time you make a change.
File > Options > Formulas > Calculation Options > Manual
- Use fewer volatile functions: Functions like NOW(), TODAY(), and INDIRECT() recalculate every time a change is made.
- Use tables instead of ranges: Structured references in tables are more efficient.
- Split large datasets: If feasible, split your data across multiple sheets or workbooks.
- Remove unnecessary formatting: Too much formatting can bloat file size and slow down processing.
6. How do you use Excel for data cleaning?
Data cleaning is one of the first and most important steps in data analysis, and Excel provides multiple ways to do this:
- Remove duplicates: Easily eliminate duplicate entries.
- Text to Columns: Split data in one column into multiple columns (e.g., splitting full names into first and last names).
- TRIM(): Remove extra spaces from text.
- FIND() and SUBSTITUTE(): For locating and replacing specific characters or substrings.
7. What are some advanced Excel functions you’ve used for data analysis?
Aside from the basics, some advanced Excel functions you might mention include:
- ARRAYFORMULA(): Allows multiple calculations to be performed at once.
- OFFSET(): Returns a range that is offset from a starting point.
- FORECAST(): Predicts future values based on historical data.
- POWER QUERY: For data extraction, transformation, and loading (ETL) tasks.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://news.1rj.ru/str/DataSimplifier
Like for more Interview Resources ♥️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
❤4
Quick Power BI Dax Revision
1. Measures: Measures in DAX are calculations that are used in Power BI to perform aggregations, calculations, and comparisons on data. They are defined using the DEFINE MEASURE or CALCULATE functions.
2. Calculated Columns: Calculated columns are columns that are created in a table by using DAX expressions. They are calculated row by row when the data is loaded into the model.
3. DAX Functions: DAX provides a wide range of functions for data manipulation and calculation. Some common functions include SUM, AVERAGE, COUNT, FILTER, CALCULATE, RELATED, ALL, ALLEXCEPT, and many more.
4. Context: DAX calculations are performed within a context, which can be row context or filter context. Understanding how context works is crucial for writing accurate DAX expressions.
5. Relationships: Power BI data models are built on relationships between tables. DAX expressions can leverage these relationships to perform calculations across related tables.
6. Time Intelligence Functions: DAX includes a set of time intelligence functions that enable you to perform calculations based on dates and time periods. Examples include TOTALYTD, SAMEPERIODLASTYEAR, DATESBETWEEN, etc.
7. Variables: DAX allows you to declare and use variables within expressions to improve readability and performance of complex calculations.
8. Aggregation Functions: DAX provides aggregation functions like SUMX, AVERAGEX, COUNTX that allow you to iterate over a table and perform aggregations based on specified conditions.
9. Logical Functions: DAX includes logical functions such as IF, AND, OR, SWITCH that help in implementing conditional logic within calculations.
10. Error Handling: DAX provides functions like ISBLANK, IFERROR, BLANK, etc., for handling errors and missing data in calculations.
1. Measures: Measures in DAX are calculations that are used in Power BI to perform aggregations, calculations, and comparisons on data. They are defined using the DEFINE MEASURE or CALCULATE functions.
2. Calculated Columns: Calculated columns are columns that are created in a table by using DAX expressions. They are calculated row by row when the data is loaded into the model.
3. DAX Functions: DAX provides a wide range of functions for data manipulation and calculation. Some common functions include SUM, AVERAGE, COUNT, FILTER, CALCULATE, RELATED, ALL, ALLEXCEPT, and many more.
4. Context: DAX calculations are performed within a context, which can be row context or filter context. Understanding how context works is crucial for writing accurate DAX expressions.
5. Relationships: Power BI data models are built on relationships between tables. DAX expressions can leverage these relationships to perform calculations across related tables.
6. Time Intelligence Functions: DAX includes a set of time intelligence functions that enable you to perform calculations based on dates and time periods. Examples include TOTALYTD, SAMEPERIODLASTYEAR, DATESBETWEEN, etc.
7. Variables: DAX allows you to declare and use variables within expressions to improve readability and performance of complex calculations.
8. Aggregation Functions: DAX provides aggregation functions like SUMX, AVERAGEX, COUNTX that allow you to iterate over a table and perform aggregations based on specified conditions.
9. Logical Functions: DAX includes logical functions such as IF, AND, OR, SWITCH that help in implementing conditional logic within calculations.
10. Error Handling: DAX provides functions like ISBLANK, IFERROR, BLANK, etc., for handling errors and missing data in calculations.
❤2
Data-Driven Decision Making
Data-driven decision-making (DDDM) involves using data analytics to guide business strategies instead of relying on intuition. Key techniques include A/B testing, forecasting, trend analysis, and KPI evaluation.
1️⃣ A/B Testing & Hypothesis Testing
A/B testing compares two versions of a product, marketing campaign, or website feature to determine which performs better.
✔ Key Metrics in A/B Testing:
Conversion Rate
Click-Through Rate (CTR)
Revenue per User
✔ Steps in A/B Testing:
1. Define the hypothesis (e.g., "Changing the CTA button color will increase clicks").
2. Split users into Group A (control) and Group B (test).
3. Analyze differences using statistical tests.
✔ SQL for A/B Testing:
Calculate average purchase per user in two test groups
Run a t-test to check statistical significance (Python)
🔹 P-value < 0.05 → Statistically significant difference.
🔹 P-value > 0.05 → No strong evidence of difference.
2️⃣ Forecasting & Trend Analysis
Forecasting predicts future trends based on historical data.
✔ Time Series Analysis Techniques:
Moving Averages (smooth trends)
Exponential Smoothing (weights recent data more)
ARIMA Models (AutoRegressive Integrated Moving Average)
✔ SQL for Moving Averages:
7-day moving average of sales
✔ Python for Forecasting (Using Prophet)
3️⃣ KPI & Metrics Analysis
KPIs (Key Performance Indicators) measure business performance.
✔ Common Business KPIs:
Revenue Growth Rate → (Current Revenue - Previous Revenue) / Previous Revenue
Customer Retention Rate → Customers at End / Customers at Start
Churn Rate → % of customers lost over time
Net Promoter Score (NPS) → Measures customer satisfaction
✔ SQL for KPI Analysis:
Calculate Monthly Revenue Growth
✔ Python for KPI Dashboard (Using Matplotlib)
4️⃣ Real-Life Use Cases of Data-Driven Decisions
📌 E-commerce: Optimize pricing based on customer demand trends.
📌 Finance: Predict stock prices using time series forecasting.
📌 Marketing: Improve email campaign conversion rates with A/B testing.
📌 Healthcare: Identify disease patterns using predictive analytics.
Mini Task for You: Write an SQL query to calculate the customer churn rate for a subnoscription-based company.
Data Analyst Roadmap: 👇
https://news.1rj.ru/str/sqlspecialist/1159
Like this post if you want me to continue covering all the topics! ❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
Data-driven decision-making (DDDM) involves using data analytics to guide business strategies instead of relying on intuition. Key techniques include A/B testing, forecasting, trend analysis, and KPI evaluation.
1️⃣ A/B Testing & Hypothesis Testing
A/B testing compares two versions of a product, marketing campaign, or website feature to determine which performs better.
✔ Key Metrics in A/B Testing:
Conversion Rate
Click-Through Rate (CTR)
Revenue per User
✔ Steps in A/B Testing:
1. Define the hypothesis (e.g., "Changing the CTA button color will increase clicks").
2. Split users into Group A (control) and Group B (test).
3. Analyze differences using statistical tests.
✔ SQL for A/B Testing:
Calculate average purchase per user in two test groups
SELECT test_group, AVG(purchase_amount) AS avg_purchase
FROM ab_test_results
GROUP BY test_group;
Run a t-test to check statistical significance (Python)
from scipy.stats import ttest_ind
t_stat, p_value = ttest_ind(group_A['conversion_rate'], group_B['conversion_rate'])
print(f"T-statistic: {t_stat}, P-value: {p_value}")
🔹 P-value < 0.05 → Statistically significant difference.
🔹 P-value > 0.05 → No strong evidence of difference.
2️⃣ Forecasting & Trend Analysis
Forecasting predicts future trends based on historical data.
✔ Time Series Analysis Techniques:
Moving Averages (smooth trends)
Exponential Smoothing (weights recent data more)
ARIMA Models (AutoRegressive Integrated Moving Average)
✔ SQL for Moving Averages:
7-day moving average of sales
SELECT order_date,
sales,
AVG(sales) OVER (ORDER BY order_date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW) AS moving_avg
FROM sales_data;
✔ Python for Forecasting (Using Prophet)
from fbprophet import Prophet
model = Prophet()
model.fit(df)
future = model.make_future_dataframe(periods=30)
forecast = model.predict(future)
model.plot(forecast)
3️⃣ KPI & Metrics Analysis
KPIs (Key Performance Indicators) measure business performance.
✔ Common Business KPIs:
Revenue Growth Rate → (Current Revenue - Previous Revenue) / Previous Revenue
Customer Retention Rate → Customers at End / Customers at Start
Churn Rate → % of customers lost over time
Net Promoter Score (NPS) → Measures customer satisfaction
✔ SQL for KPI Analysis:
Calculate Monthly Revenue Growth
SELECT month,
revenue,
LAG(revenue) OVER (ORDER BY month) AS prev_month_revenue,
(revenue - prev_month_revenue) / prev_month_revenue * 100 AS growth_rate
FROM revenue_data;
✔ Python for KPI Dashboard (Using Matplotlib)
import matplotlib.pyplot as plt
plt.plot(df['month'], df['revenue_growth'], marker='o')
plt.noscript('Monthly Revenue Growth')
plt.xlabel('Month')
plt.ylabel('Growth Rate (%)')
plt.show()
4️⃣ Real-Life Use Cases of Data-Driven Decisions
📌 E-commerce: Optimize pricing based on customer demand trends.
📌 Finance: Predict stock prices using time series forecasting.
📌 Marketing: Improve email campaign conversion rates with A/B testing.
📌 Healthcare: Identify disease patterns using predictive analytics.
Mini Task for You: Write an SQL query to calculate the customer churn rate for a subnoscription-based company.
Data Analyst Roadmap: 👇
https://news.1rj.ru/str/sqlspecialist/1159
Like this post if you want me to continue covering all the topics! ❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
❤4
A step-by-step guide to land a job as a data analyst
Landing your first data analyst job is toughhhhh.
Here are 11 tips to make it easier:
- Master SQL.
- Next, learn a BI tool.
- Drink lots of tea or coffee.
- Tackle relevant data projects.
- Create a relevant data portfolio.
- Focus on actionable data insights.
- Remember imposter syndrome is normal.
- Find ways to prove you’re a problem-solver.
- Develop compelling data visualization stories.
- Engage with LinkedIn posts from fellow analysts.
- Illustrate your analytical impact with metrics & KPIs.
- Share your career story & insights via LinkedIn posts.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope this helps you 😊
Landing your first data analyst job is toughhhhh.
Here are 11 tips to make it easier:
- Master SQL.
- Next, learn a BI tool.
- Drink lots of tea or coffee.
- Tackle relevant data projects.
- Create a relevant data portfolio.
- Focus on actionable data insights.
- Remember imposter syndrome is normal.
- Find ways to prove you’re a problem-solver.
- Develop compelling data visualization stories.
- Engage with LinkedIn posts from fellow analysts.
- Illustrate your analytical impact with metrics & KPIs.
- Share your career story & insights via LinkedIn posts.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope this helps you 😊
❤2
𝐓𝐢𝐩𝐬 𝐟𝐨𝐫 𝐏𝐲𝐭𝐡𝐨𝐧 𝐂𝐨𝐝𝐢𝐧𝐠 𝐢𝐧 𝐃𝐚𝐭𝐚 𝐀𝐧𝐚𝐥𝐲𝐭𝐢𝐜𝐬:
𝘐 𝘨𝘦𝘵 𝘴𝘰 𝘮𝘢𝘯𝘺 𝘲𝘶𝘦𝘴𝘵𝘪𝘰𝘯𝘴 𝘧𝘳𝘰𝘮 𝘥𝘢𝘵𝘢 𝘢𝘯𝘢𝘭𝘺𝘵𝘪𝘤𝘴 𝘢𝘴𝘱𝘪𝘳𝘢𝘯𝘵𝘴 𝘢𝘯𝘥 𝘱𝘳𝘰𝘧𝘦𝘴𝘴𝘪𝘰𝘯𝘢𝘭𝘴 𝘰𝘯 𝘩𝘰𝘸 𝘵𝘰 𝘨𝘢𝘪𝘯 𝘤𝘰𝘮𝘮𝘢𝘯𝘥 𝘰𝘧 𝘗𝘺𝘵𝘩𝘰𝘯.
📍𝐋𝐞𝐚𝐫𝐧 𝐂𝐨𝐫𝐞 𝐏𝐲𝐭𝐡𝐨𝐧 𝐋𝐢𝐛𝐫𝐚𝐫𝐢𝐞𝐬: Master Python libraries for data analytics, like
-pandas for dataframes,
-NumPy for numerical operations,
-Matplotlib/Seaborn for plotting,
-scikit-learn for machine learning.
📍𝐔𝐧𝐝𝐞𝐫𝐬𝐭𝐚𝐧𝐝 𝐂𝐨𝐧𝐜𝐞𝐩𝐭𝐬: Important concepts like list comprehensions, lambda functions, object-oriented programming, and error handling to write efficient code.
📍𝐔𝐬𝐞 𝐏𝐫𝐨𝐛𝐥𝐞𝐦-𝐒𝐨𝐥𝐯𝐢𝐧𝐠 𝐌𝐞𝐭𝐡𝐨𝐝𝐬: Apply data wrangling techniques, efficient loops, and vectorized operations in NumPy/pandas for optimized performance.
📍𝐃𝐨 𝐌𝐨𝐜𝐤 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬: Work on end-to-end Python analytics projects—data loading, cleaning, analysis, and visualization.
📍𝐋𝐞𝐚𝐫𝐧 𝐟𝐫𝐨𝐦 𝐏𝐚𝐬𝐭 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬: Review your previous Python projects to see where your code can be more efficient.
Like this post if you need more resources like this 👍❤️
𝘐 𝘨𝘦𝘵 𝘴𝘰 𝘮𝘢𝘯𝘺 𝘲𝘶𝘦𝘴𝘵𝘪𝘰𝘯𝘴 𝘧𝘳𝘰𝘮 𝘥𝘢𝘵𝘢 𝘢𝘯𝘢𝘭𝘺𝘵𝘪𝘤𝘴 𝘢𝘴𝘱𝘪𝘳𝘢𝘯𝘵𝘴 𝘢𝘯𝘥 𝘱𝘳𝘰𝘧𝘦𝘴𝘴𝘪𝘰𝘯𝘢𝘭𝘴 𝘰𝘯 𝘩𝘰𝘸 𝘵𝘰 𝘨𝘢𝘪𝘯 𝘤𝘰𝘮𝘮𝘢𝘯𝘥 𝘰𝘧 𝘗𝘺𝘵𝘩𝘰𝘯.
📍𝐋𝐞𝐚𝐫𝐧 𝐂𝐨𝐫𝐞 𝐏𝐲𝐭𝐡𝐨𝐧 𝐋𝐢𝐛𝐫𝐚𝐫𝐢𝐞𝐬: Master Python libraries for data analytics, like
-pandas for dataframes,
-NumPy for numerical operations,
-Matplotlib/Seaborn for plotting,
-scikit-learn for machine learning.
📍𝐔𝐧𝐝𝐞𝐫𝐬𝐭𝐚𝐧𝐝 𝐂𝐨𝐧𝐜𝐞𝐩𝐭𝐬: Important concepts like list comprehensions, lambda functions, object-oriented programming, and error handling to write efficient code.
📍𝐔𝐬𝐞 𝐏𝐫𝐨𝐛𝐥𝐞𝐦-𝐒𝐨𝐥𝐯𝐢𝐧𝐠 𝐌𝐞𝐭𝐡𝐨𝐝𝐬: Apply data wrangling techniques, efficient loops, and vectorized operations in NumPy/pandas for optimized performance.
📍𝐃𝐨 𝐌𝐨𝐜𝐤 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬: Work on end-to-end Python analytics projects—data loading, cleaning, analysis, and visualization.
📍𝐋𝐞𝐚𝐫𝐧 𝐟𝐫𝐨𝐦 𝐏𝐚𝐬𝐭 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬: Review your previous Python projects to see where your code can be more efficient.
Like this post if you need more resources like this 👍❤️
❤2
1. Does SQL support programming language features?
It is true that SQL is a language, but it does not support programming as it is not a programming language, it is a command language. We do not have some programming concepts in SQL like for loops or while loop, we only have commands which we can use to query, update, delete, etc. data in the database. SQL allows us to manipulate data in a database.
2. What is a trigger?
Trigger is a statement that a system executes automatically when there is any modification to the database. In a trigger, we first specify when the trigger is to be executed and then the action to be performed when the trigger executes. Triggers are used to specify certain integrity constraints and referential constraints that cannot be specified using the constraint mechanism of SQL.
3. What are aggregate and scalar functions?
For doing operations on data SQL has many built-in functions, they are categorized into two categories and further sub-categorized into seven different functions under each category. The categories are:
Aggregate functions:
These functions are used to do operations from the values of the column and a single value is returned.
Scalar functions:
These functions are based on user input, these too return a single value.
4. Define SQL Order by the statement?
The ORDER BY statement in SQL is used to sort the fetched data in either ascending or descending according to one or more columns.
By default ORDER BY sorts the data in ascending order.
We can use the keyword DESC to sort the data in descending order and the keyword ASC to sort in ascending order.
5. What is the difference between primary key and unique constraints?
The primary key cannot have NULL values, the unique constraints can have NULL values. There is only one primary key in a table, but there can be multiple unique constraints. The primary key creates the clustered index automatically but the unique key does not.
It is true that SQL is a language, but it does not support programming as it is not a programming language, it is a command language. We do not have some programming concepts in SQL like for loops or while loop, we only have commands which we can use to query, update, delete, etc. data in the database. SQL allows us to manipulate data in a database.
2. What is a trigger?
Trigger is a statement that a system executes automatically when there is any modification to the database. In a trigger, we first specify when the trigger is to be executed and then the action to be performed when the trigger executes. Triggers are used to specify certain integrity constraints and referential constraints that cannot be specified using the constraint mechanism of SQL.
3. What are aggregate and scalar functions?
For doing operations on data SQL has many built-in functions, they are categorized into two categories and further sub-categorized into seven different functions under each category. The categories are:
Aggregate functions:
These functions are used to do operations from the values of the column and a single value is returned.
Scalar functions:
These functions are based on user input, these too return a single value.
4. Define SQL Order by the statement?
The ORDER BY statement in SQL is used to sort the fetched data in either ascending or descending according to one or more columns.
By default ORDER BY sorts the data in ascending order.
We can use the keyword DESC to sort the data in descending order and the keyword ASC to sort in ascending order.
5. What is the difference between primary key and unique constraints?
The primary key cannot have NULL values, the unique constraints can have NULL values. There is only one primary key in a table, but there can be multiple unique constraints. The primary key creates the clustered index automatically but the unique key does not.
❤2
Data Analyst INTERVIEW QUESTIONS AND ANSWERS
👇👇
1.Can you name the wildcards in Excel?
Ans: There are 3 wildcards in Excel that can ve used in formulas.
Asterisk (*) – 0 or more characters. For example, Ex* could mean Excel, Extra, Expertise, etc.
Question mark (?) – Represents any 1 character. For example, R?ain may mean Rain or Ruin.
Tilde (~) – Used to identify a wildcard character (~, *, ?). For example, If you need to find the exact phrase India* in a list. If you use India* as the search string, you may get any word with India at the beginning followed by different characters (such as Indian, Indiana). If you have to look for India” exclusively, use ~.
Hence, the search string will be india~*. ~ is used to ensure that the spreadsheet reads the following character as is, and not as a wildcard.
2.What is cascading filter in tableau?
Ans: Cascading filters can also be understood as giving preference to a particular filter and then applying other filters on previously filtered data source. Right-click on the filter you want to use as a main filter and make sure it is set as all values in dashboard then select the subsequent filter and select only relevant values to cascade the filters. This will improve the performance of the dashboard as you have decreased the time wasted in running all the filters over complete data source.
3.What is the difference between .twb and .twbx extension?
Ans:
A .twb file contains information on all the sheets, dashboards and stories, but it won’t contain any information regarding data source. Whereas .twbx file contains all the sheets, dashboards, stories and also compressed data sources. For saving a .twbx extract needs to be performed on the data source. If we forward .twb file to someone else than they will be able to see the worksheets and dashboards but won’t be able to look into the dataset.
4.What are the various Power BI versions?
Power BI Premium capacity-based license, for example, allows users with a free license to act on content in workspaces with Premium capacity. A user with a free license can only use the Power BI service to connect to data and produce reports and dashboards in My Workspace outside of Premium capacity. They are unable to exchange material or publish it in other workspaces. To process material, a Power BI license with a free or Pro per-user license only uses a shared and restricted capacity. Users with a Power BI Pro license can only work with other Power BI Pro users if the material is stored in that shared capacity. They may consume user-generated information, post material to app workspaces, share dashboards, and subscribe to dashboards and reports. Pro users can share material with users who don’t have a Power BI Pro subnoscription while workspaces are at Premium capacity.
ENJOY LEARNING 👍👍
👇👇
1.Can you name the wildcards in Excel?
Ans: There are 3 wildcards in Excel that can ve used in formulas.
Asterisk (*) – 0 or more characters. For example, Ex* could mean Excel, Extra, Expertise, etc.
Question mark (?) – Represents any 1 character. For example, R?ain may mean Rain or Ruin.
Tilde (~) – Used to identify a wildcard character (~, *, ?). For example, If you need to find the exact phrase India* in a list. If you use India* as the search string, you may get any word with India at the beginning followed by different characters (such as Indian, Indiana). If you have to look for India” exclusively, use ~.
Hence, the search string will be india~*. ~ is used to ensure that the spreadsheet reads the following character as is, and not as a wildcard.
2.What is cascading filter in tableau?
Ans: Cascading filters can also be understood as giving preference to a particular filter and then applying other filters on previously filtered data source. Right-click on the filter you want to use as a main filter and make sure it is set as all values in dashboard then select the subsequent filter and select only relevant values to cascade the filters. This will improve the performance of the dashboard as you have decreased the time wasted in running all the filters over complete data source.
3.What is the difference between .twb and .twbx extension?
Ans:
A .twb file contains information on all the sheets, dashboards and stories, but it won’t contain any information regarding data source. Whereas .twbx file contains all the sheets, dashboards, stories and also compressed data sources. For saving a .twbx extract needs to be performed on the data source. If we forward .twb file to someone else than they will be able to see the worksheets and dashboards but won’t be able to look into the dataset.
4.What are the various Power BI versions?
Power BI Premium capacity-based license, for example, allows users with a free license to act on content in workspaces with Premium capacity. A user with a free license can only use the Power BI service to connect to data and produce reports and dashboards in My Workspace outside of Premium capacity. They are unable to exchange material or publish it in other workspaces. To process material, a Power BI license with a free or Pro per-user license only uses a shared and restricted capacity. Users with a Power BI Pro license can only work with other Power BI Pro users if the material is stored in that shared capacity. They may consume user-generated information, post material to app workspaces, share dashboards, and subscribe to dashboards and reports. Pro users can share material with users who don’t have a Power BI Pro subnoscription while workspaces are at Premium capacity.
ENJOY LEARNING 👍👍
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Here are some essential SQL tips for beginners 👇👇
◆ Primary Key = Unique Key + Not Null constraint
◆ To perform case insensitive search use UPPER() function ex. UPPER(customer_name) LIKE ‘A%A’
◆ LIKE operator is for string data type
◆ COUNT(*), COUNT(1), COUNT(0) all are same
◆ All aggregate functions ignore the NULL values
◆ Aggregate functions MIN, MAX, SUM, AVG, COUNT are for int data type whereas STRING_AGG is for string data type
◆ For row level filtration use WHERE and aggregate level filtration use HAVING
◆ UNION ALL will include duplicates where as UNION excludes duplicates
◆ If the results will not have any duplicates, use UNION ALL instead of UNION
◆ We have to alias the subquery if we are using the columns in the outer select query
◆ Subqueries can be used as output with NOT IN condition.
◆ CTEs look better than subqueries. Performance wise both are same.
◆ When joining two tables , if one table has only one value then we can use 1=1 as a condition to join the tables. This will be considered as CROSS JOIN.
◆ Window functions work at ROW level.
◆ The difference between RANK() and DENSE_RANK() is that RANK() skips the rank if the values are the same.
◆ EXISTS works on true/false conditions. If the query returns at least one value, the condition is TRUE. All the records corresponding to the conditions are returned.
Like for more 😄😄
◆ Primary Key = Unique Key + Not Null constraint
◆ To perform case insensitive search use UPPER() function ex. UPPER(customer_name) LIKE ‘A%A’
◆ LIKE operator is for string data type
◆ COUNT(*), COUNT(1), COUNT(0) all are same
◆ All aggregate functions ignore the NULL values
◆ Aggregate functions MIN, MAX, SUM, AVG, COUNT are for int data type whereas STRING_AGG is for string data type
◆ For row level filtration use WHERE and aggregate level filtration use HAVING
◆ UNION ALL will include duplicates where as UNION excludes duplicates
◆ If the results will not have any duplicates, use UNION ALL instead of UNION
◆ We have to alias the subquery if we are using the columns in the outer select query
◆ Subqueries can be used as output with NOT IN condition.
◆ CTEs look better than subqueries. Performance wise both are same.
◆ When joining two tables , if one table has only one value then we can use 1=1 as a condition to join the tables. This will be considered as CROSS JOIN.
◆ Window functions work at ROW level.
◆ The difference between RANK() and DENSE_RANK() is that RANK() skips the rank if the values are the same.
◆ EXISTS works on true/false conditions. If the query returns at least one value, the condition is TRUE. All the records corresponding to the conditions are returned.
Like for more 😄😄
❤2
Top interview SQL questions, including both technical and non-technical questions, along with their answers PART-1
1. What is SQL?
- Answer: SQL (Structured Query Language) is a standard programming language specifically designed for managing and manipulating relational databases.
2. What are the different types of SQL statements?
- Answer: SQL statements can be classified into DDL (Data Definition Language), DML (Data Manipulation Language), DCL (Data Control Language), and TCL (Transaction Control Language).
3. What is a primary key?
- Answer: A primary key is a field (or combination of fields) in a table that uniquely identifies each row/record in that table.
4. What is a foreign key?
- Answer: A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table or the same table. It establishes a link between the data in two tables.
5. What are joins? Explain different types of joins.
- Answer: A join is an SQL operation for combining records from two or more tables. Types of joins include INNER JOIN, LEFT JOIN (or LEFT OUTER JOIN), RIGHT JOIN (or RIGHT OUTER JOIN), and FULL JOIN (or FULL OUTER JOIN).
6. What is normalization?
- Answer: Normalization is the process of organizing data to reduce redundancy and improve data integrity. This typically involves dividing a database into two or more tables and defining relationships between them.
7. What is denormalization?
- Answer: Denormalization is the process of combining normalized tables into fewer tables to improve database read performance, sometimes at the expense of write performance and data integrity.
8. What is stored procedure?
- Answer: A stored procedure is a prepared SQL code that you can save and reuse. So, if you have an SQL query that you write frequently, you can save it as a stored procedure and then call it to execute it.
9. What is an index?
- Answer: An index is a database object that improves the speed of data retrieval operations on a table at the cost of additional storage and maintenance overhead.
10. What is a view in SQL?
- Answer: A view is a virtual table based on the result set of an SQL query. It contains rows and columns, just like a real table, but does not physically store the data.
11. What is a subquery?
- Answer: A subquery is an SQL query nested inside a larger query. It is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.
12. What are aggregate functions in SQL?
- Answer: Aggregate functions perform a calculation on a set of values and return a single value. Examples include COUNT, SUM, AVG (average), MIN (minimum), and MAX (maximum).
13. Difference between DELETE and TRUNCATE?
- Answer: DELETE removes rows one at a time and logs each delete, while TRUNCATE removes all rows in a table without logging individual row deletions. TRUNCATE is faster but cannot be rolled back.
14. What is a UNION in SQL?
- Answer: UNION is an operator used to combine the result sets of two or more SELECT statements. It removes duplicate rows between the various SELECT statements.
15. What is a cursor in SQL?
- Answer: A cursor is a database object used to retrieve, manipulate, and navigate through a result set one row at a time.
16. What is trigger in SQL?
- Answer: A trigger is a set of SQL statements that automatically execute or "trigger" when certain events occur in a database, such as INSERT, UPDATE, or DELETE.
17. Difference between clustered and non-clustered indexes?
- Answer: A clustered index determines the physical order of data in a table and can only be one per table. A non-clustered index, on the other hand, creates a logical order and can be many per table.
18. Explain the term ACID.
- Answer: ACID stands for Atomicity, Consistency, Isolation, and Durability.
SQL Resources: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Hope it helps :)
1. What is SQL?
- Answer: SQL (Structured Query Language) is a standard programming language specifically designed for managing and manipulating relational databases.
2. What are the different types of SQL statements?
- Answer: SQL statements can be classified into DDL (Data Definition Language), DML (Data Manipulation Language), DCL (Data Control Language), and TCL (Transaction Control Language).
3. What is a primary key?
- Answer: A primary key is a field (or combination of fields) in a table that uniquely identifies each row/record in that table.
4. What is a foreign key?
- Answer: A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table or the same table. It establishes a link between the data in two tables.
5. What are joins? Explain different types of joins.
- Answer: A join is an SQL operation for combining records from two or more tables. Types of joins include INNER JOIN, LEFT JOIN (or LEFT OUTER JOIN), RIGHT JOIN (or RIGHT OUTER JOIN), and FULL JOIN (or FULL OUTER JOIN).
6. What is normalization?
- Answer: Normalization is the process of organizing data to reduce redundancy and improve data integrity. This typically involves dividing a database into two or more tables and defining relationships between them.
7. What is denormalization?
- Answer: Denormalization is the process of combining normalized tables into fewer tables to improve database read performance, sometimes at the expense of write performance and data integrity.
8. What is stored procedure?
- Answer: A stored procedure is a prepared SQL code that you can save and reuse. So, if you have an SQL query that you write frequently, you can save it as a stored procedure and then call it to execute it.
9. What is an index?
- Answer: An index is a database object that improves the speed of data retrieval operations on a table at the cost of additional storage and maintenance overhead.
10. What is a view in SQL?
- Answer: A view is a virtual table based on the result set of an SQL query. It contains rows and columns, just like a real table, but does not physically store the data.
11. What is a subquery?
- Answer: A subquery is an SQL query nested inside a larger query. It is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.
12. What are aggregate functions in SQL?
- Answer: Aggregate functions perform a calculation on a set of values and return a single value. Examples include COUNT, SUM, AVG (average), MIN (minimum), and MAX (maximum).
13. Difference between DELETE and TRUNCATE?
- Answer: DELETE removes rows one at a time and logs each delete, while TRUNCATE removes all rows in a table without logging individual row deletions. TRUNCATE is faster but cannot be rolled back.
14. What is a UNION in SQL?
- Answer: UNION is an operator used to combine the result sets of two or more SELECT statements. It removes duplicate rows between the various SELECT statements.
15. What is a cursor in SQL?
- Answer: A cursor is a database object used to retrieve, manipulate, and navigate through a result set one row at a time.
16. What is trigger in SQL?
- Answer: A trigger is a set of SQL statements that automatically execute or "trigger" when certain events occur in a database, such as INSERT, UPDATE, or DELETE.
17. Difference between clustered and non-clustered indexes?
- Answer: A clustered index determines the physical order of data in a table and can only be one per table. A non-clustered index, on the other hand, creates a logical order and can be many per table.
18. Explain the term ACID.
- Answer: ACID stands for Atomicity, Consistency, Isolation, and Durability.
SQL Resources: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Hope it helps :)
❤2
Interview guide for Data Analyst Role
When interviewing for a Data Analyst role as a fresher, you’ll likely encounter questions that focus on your understanding of data analysis concepts, technical skills, and problem-solving abilities. Here’s a comprehensive list of commonly asked interview questions:
1. General and Behavioral Questions
• Tell me about yourself.
• Why do you want to become a Data Analyst?
• What do you know about our company and why do you want to work here?
• Describe a time when you solved a problem using data.
• How do you prioritize tasks and manage deadlines?
• Tell me about a time when you worked in a team to complete a project.
2. Technical Questions
• What are the different types of joins in SQL? (Expect variations of SQL questions)
• How would you handle missing or inconsistent data?
• What is normalization? Why is it important?
• Explain the difference between primary keys and foreign keys in a database.
• What are the most common data types in SQL?
• How do you perform data cleaning in Excel?
3. Analytical Skills and Problem-Solving
• How would you find outliers in a dataset?
• How would you approach analyzing a dataset with 1 million rows?
• If given two datasets, how would you combine them?
• What steps would you take if your results didn’t match stakeholders’ expectations?
• How would you identify trends or patterns in a dataset?
4. Excel-Related Questions
• What are pivot tables and how do you use them?
• Explain VLOOKUP and HLOOKUP.
• How would you handle large datasets in Excel?
• What is the use of conditional formatting?
• How would you create a dashboard in Excel?
• How can you create a custom formula in Excel?
5. SQL Questions
• Write a SQL query to find the second highest salary in a table.
• What is the difference between WHERE and HAVING clauses?
• How would you optimize a slow-running query?
• What is the difference between UNION and UNION ALL?
• What is a subquery, and when would you use it?
6. Statistics and Data Analysis
• Explain the difference between mean, median, and mode.
• What is standard deviation, and why is it important?
• What is regression analysis? Can you explain linear regression?
• What is correlation, and how is it different from causation?
• What are some key metrics you would track for a marketing campaign?
7. Data Visualization and Tools
• What tools have you used for data visualization?
• Explain a situation where you used charts to tell a story.
• What is your experience with tools like Tableau or Power BI?
• How would you decide which chart type to use for visualizing data?
• Have you ever created a dashboard? If yes, what were the key features?
8. Python/R (If mentioned on your resume)
• What libraries do you use in Python for data analysis?
• How would you import a dataset and perform basic analysis in Python?
• What are some common data manipulation functions in pandas?
• How do you handle missing values in Python?
9. Scenario-Based Questions
• Imagine you are given a dataset of customer purchases; how would you segment the customers?
• You are given sales data for the past five years. What steps would you take to forecast the next year’s sales?
• If you find conflicting data in a report, how would you handle the situation?
• Describe a project where you identified key insights using data.
10. Aptitude or Logical Questions
• Some companies also include questions testing your quantitative aptitude, logical reasoning, and pattern recognition to gauge problem-solving skills.
Tips to Prepare:
1. Strengthen your Basics: Brush up on SQL, Excel, and statistical concepts.
2. Mock Interviews: Practice explaining your thought process for data problems.
3. Projects: Be ready to discuss any projects or internships you’ve done.
4. Stay Current: Read about trends in data analysis and business intelligence.
Hope this helps you 😊
When interviewing for a Data Analyst role as a fresher, you’ll likely encounter questions that focus on your understanding of data analysis concepts, technical skills, and problem-solving abilities. Here’s a comprehensive list of commonly asked interview questions:
1. General and Behavioral Questions
• Tell me about yourself.
• Why do you want to become a Data Analyst?
• What do you know about our company and why do you want to work here?
• Describe a time when you solved a problem using data.
• How do you prioritize tasks and manage deadlines?
• Tell me about a time when you worked in a team to complete a project.
2. Technical Questions
• What are the different types of joins in SQL? (Expect variations of SQL questions)
• How would you handle missing or inconsistent data?
• What is normalization? Why is it important?
• Explain the difference between primary keys and foreign keys in a database.
• What are the most common data types in SQL?
• How do you perform data cleaning in Excel?
3. Analytical Skills and Problem-Solving
• How would you find outliers in a dataset?
• How would you approach analyzing a dataset with 1 million rows?
• If given two datasets, how would you combine them?
• What steps would you take if your results didn’t match stakeholders’ expectations?
• How would you identify trends or patterns in a dataset?
4. Excel-Related Questions
• What are pivot tables and how do you use them?
• Explain VLOOKUP and HLOOKUP.
• How would you handle large datasets in Excel?
• What is the use of conditional formatting?
• How would you create a dashboard in Excel?
• How can you create a custom formula in Excel?
5. SQL Questions
• Write a SQL query to find the second highest salary in a table.
• What is the difference between WHERE and HAVING clauses?
• How would you optimize a slow-running query?
• What is the difference between UNION and UNION ALL?
• What is a subquery, and when would you use it?
6. Statistics and Data Analysis
• Explain the difference between mean, median, and mode.
• What is standard deviation, and why is it important?
• What is regression analysis? Can you explain linear regression?
• What is correlation, and how is it different from causation?
• What are some key metrics you would track for a marketing campaign?
7. Data Visualization and Tools
• What tools have you used for data visualization?
• Explain a situation where you used charts to tell a story.
• What is your experience with tools like Tableau or Power BI?
• How would you decide which chart type to use for visualizing data?
• Have you ever created a dashboard? If yes, what were the key features?
8. Python/R (If mentioned on your resume)
• What libraries do you use in Python for data analysis?
• How would you import a dataset and perform basic analysis in Python?
• What are some common data manipulation functions in pandas?
• How do you handle missing values in Python?
9. Scenario-Based Questions
• Imagine you are given a dataset of customer purchases; how would you segment the customers?
• You are given sales data for the past five years. What steps would you take to forecast the next year’s sales?
• If you find conflicting data in a report, how would you handle the situation?
• Describe a project where you identified key insights using data.
10. Aptitude or Logical Questions
• Some companies also include questions testing your quantitative aptitude, logical reasoning, and pattern recognition to gauge problem-solving skills.
Tips to Prepare:
1. Strengthen your Basics: Brush up on SQL, Excel, and statistical concepts.
2. Mock Interviews: Practice explaining your thought process for data problems.
3. Projects: Be ready to discuss any projects or internships you’ve done.
4. Stay Current: Read about trends in data analysis and business intelligence.
Hope this helps you 😊
❤4
Data Analyst Interview Questions
1. What do Tableau's sets and groups mean?
Data is grouped using sets and groups according to predefined criteria. The primary distinction between the two is that although a set can have only two options—either in or out—a group can divide the dataset into several groups. A user should decide which group or sets to apply based on the conditions.
2.What in Excel is a macro?
An Excel macro is an algorithm or a group of steps that helps automate an operation by capturing and replaying the steps needed to finish it. Once the steps have been saved, you may construct a Macro that the user can alter and replay as often as they like.
Macro is excellent for routine work because it also gets rid of mistakes. Consider the scenario when an account manager needs to share reports about staff members who owe the company money. If so, it can be automated by utilising a macro and making small adjustments each month as necessary.
3.Gantt chart in Tableau
A Tableau Gantt chart illustrates the duration of events as well as the progression of value across the period. Along with the time axis, it has bars. The Gantt chart is primarily used as a project management tool, with each bar representing a project job.
4.In Microsoft Excel, how do you create a drop-down list?
Start by selecting the Data tab from the ribbon.
Select Data Validation from the Data Tools group.
Go to Settings > Allow > List next.
Choose the source you want to offer in the form of a list array.
1. What do Tableau's sets and groups mean?
Data is grouped using sets and groups according to predefined criteria. The primary distinction between the two is that although a set can have only two options—either in or out—a group can divide the dataset into several groups. A user should decide which group or sets to apply based on the conditions.
2.What in Excel is a macro?
An Excel macro is an algorithm or a group of steps that helps automate an operation by capturing and replaying the steps needed to finish it. Once the steps have been saved, you may construct a Macro that the user can alter and replay as often as they like.
Macro is excellent for routine work because it also gets rid of mistakes. Consider the scenario when an account manager needs to share reports about staff members who owe the company money. If so, it can be automated by utilising a macro and making small adjustments each month as necessary.
3.Gantt chart in Tableau
A Tableau Gantt chart illustrates the duration of events as well as the progression of value across the period. Along with the time axis, it has bars. The Gantt chart is primarily used as a project management tool, with each bar representing a project job.
4.In Microsoft Excel, how do you create a drop-down list?
Start by selecting the Data tab from the ribbon.
Select Data Validation from the Data Tools group.
Go to Settings > Allow > List next.
Choose the source you want to offer in the form of a list array.
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