Want to become a Data Scientist?
Hereโs a quick roadmap with essential concepts:
1. Mathematics & Statistics
Linear Algebra: Matrix operations, eigenvalues, eigenvectors, and decomposition, which are crucial for machine learning.
Probability & Statistics: Hypothesis testing, probability distributions, Bayesian inference, confidence intervals, and statistical significance.
Calculus: Derivatives, integrals, and gradients, especially partial derivatives, which are essential for understanding model optimization.
2. Programming
Python or R: Choose a primary programming language for data science.
Python: Libraries like NumPy, Pandas for data manipulation, and Scikit-Learn for machine learning.
R: Especially popular in academia and finance, with libraries like dplyr and ggplot2 for data manipulation and visualization.
SQL: Master querying and database management, essential for accessing, joining, and filtering large datasets.
3. Data Wrangling & Preprocessing
Data Cleaning: Handle missing values, outliers, duplicates, and data formatting.
Feature Engineering: Create meaningful features, handle categorical variables, and apply transformations (scaling, encoding, etc.).
Exploratory Data Analysis (EDA): Visualize data distributions, correlations, and trends to generate hypotheses and insights.
4. Data Visualization
Python Libraries: Use Matplotlib, Seaborn, and Plotly to visualize data.
Tableau or Power BI: Learn interactive visualization tools for building dashboards.
Storytelling: Develop skills to interpret and present data in a meaningful way to stakeholders.
5. Machine Learning
Supervised Learning: Understand algorithms like Linear Regression, Logistic Regression, Decision Trees, Random Forest, Gradient Boosting, and Support Vector Machines (SVM).
Unsupervised Learning: Study clustering (K-means, DBSCAN) and dimensionality reduction (PCA, t-SNE).
Evaluation Metrics: Understand accuracy, precision, recall, F1-score for classification and RMSE, MAE for regression.
6. Advanced Machine Learning & Deep Learning
Neural Networks: Understand the basics of neural networks and backpropagation.
Deep Learning: Get familiar with Convolutional Neural Networks (CNNs) for image processing and Recurrent Neural Networks (RNNs) for sequential data.
Transfer Learning: Apply pre-trained models for specific use cases.
Frameworks: Use TensorFlow Keras for building deep learning models.
7. Natural Language Processing (NLP)
Text Preprocessing: Tokenization, stemming, lemmatization, stop-word removal.
NLP Techniques: Understand bag-of-words, TF-IDF, and word embeddings (Word2Vec, GloVe).
NLP Models: Work with recurrent neural networks (RNNs), transformers (BERT, GPT) for text classification, sentiment analysis, and translation.
8. Big Data Tools (Optional)
Distributed Data Processing: Learn Hadoop and Spark for handling large datasets. Use Google BigQuery for big data storage and processing.
9. Data Science Workflows & Pipelines (Optional)
ETL & Data Pipelines: Extract, Transform, and Load data using tools like Apache Airflow for automation. Set up reproducible workflows for data transformation, modeling, and monitoring.
Model Deployment: Deploy models in production using Flask, FastAPI, or cloud services (AWS SageMaker, Google AI Platform).
10. Model Validation & Tuning
Cross-Validation: Techniques like K-fold cross-validation to avoid overfitting.
Hyperparameter Tuning: Use Grid Search, Random Search, and Bayesian Optimization to optimize model performance.
Bias-Variance Trade-off: Understand how to balance bias and variance in models for better generalization.
11. Time Series Analysis
Statistical Models: ARIMA, SARIMA, and Holt-Winters for time-series forecasting.
Time Series: Handle seasonality, trends, and lags. Use LSTMs or Prophet for more advanced time-series forecasting.
12. Experimentation & A/B Testing
Experiment Design: Learn how to set up and analyze controlled experiments.
A/B Testing: Statistical techniques for comparing groups & measuring the impact of changes.
ENJOY LEARNING ๐๐
#datascience
Hereโs a quick roadmap with essential concepts:
1. Mathematics & Statistics
Linear Algebra: Matrix operations, eigenvalues, eigenvectors, and decomposition, which are crucial for machine learning.
Probability & Statistics: Hypothesis testing, probability distributions, Bayesian inference, confidence intervals, and statistical significance.
Calculus: Derivatives, integrals, and gradients, especially partial derivatives, which are essential for understanding model optimization.
2. Programming
Python or R: Choose a primary programming language for data science.
Python: Libraries like NumPy, Pandas for data manipulation, and Scikit-Learn for machine learning.
R: Especially popular in academia and finance, with libraries like dplyr and ggplot2 for data manipulation and visualization.
SQL: Master querying and database management, essential for accessing, joining, and filtering large datasets.
3. Data Wrangling & Preprocessing
Data Cleaning: Handle missing values, outliers, duplicates, and data formatting.
Feature Engineering: Create meaningful features, handle categorical variables, and apply transformations (scaling, encoding, etc.).
Exploratory Data Analysis (EDA): Visualize data distributions, correlations, and trends to generate hypotheses and insights.
4. Data Visualization
Python Libraries: Use Matplotlib, Seaborn, and Plotly to visualize data.
Tableau or Power BI: Learn interactive visualization tools for building dashboards.
Storytelling: Develop skills to interpret and present data in a meaningful way to stakeholders.
5. Machine Learning
Supervised Learning: Understand algorithms like Linear Regression, Logistic Regression, Decision Trees, Random Forest, Gradient Boosting, and Support Vector Machines (SVM).
Unsupervised Learning: Study clustering (K-means, DBSCAN) and dimensionality reduction (PCA, t-SNE).
Evaluation Metrics: Understand accuracy, precision, recall, F1-score for classification and RMSE, MAE for regression.
6. Advanced Machine Learning & Deep Learning
Neural Networks: Understand the basics of neural networks and backpropagation.
Deep Learning: Get familiar with Convolutional Neural Networks (CNNs) for image processing and Recurrent Neural Networks (RNNs) for sequential data.
Transfer Learning: Apply pre-trained models for specific use cases.
Frameworks: Use TensorFlow Keras for building deep learning models.
7. Natural Language Processing (NLP)
Text Preprocessing: Tokenization, stemming, lemmatization, stop-word removal.
NLP Techniques: Understand bag-of-words, TF-IDF, and word embeddings (Word2Vec, GloVe).
NLP Models: Work with recurrent neural networks (RNNs), transformers (BERT, GPT) for text classification, sentiment analysis, and translation.
8. Big Data Tools (Optional)
Distributed Data Processing: Learn Hadoop and Spark for handling large datasets. Use Google BigQuery for big data storage and processing.
9. Data Science Workflows & Pipelines (Optional)
ETL & Data Pipelines: Extract, Transform, and Load data using tools like Apache Airflow for automation. Set up reproducible workflows for data transformation, modeling, and monitoring.
Model Deployment: Deploy models in production using Flask, FastAPI, or cloud services (AWS SageMaker, Google AI Platform).
10. Model Validation & Tuning
Cross-Validation: Techniques like K-fold cross-validation to avoid overfitting.
Hyperparameter Tuning: Use Grid Search, Random Search, and Bayesian Optimization to optimize model performance.
Bias-Variance Trade-off: Understand how to balance bias and variance in models for better generalization.
11. Time Series Analysis
Statistical Models: ARIMA, SARIMA, and Holt-Winters for time-series forecasting.
Time Series: Handle seasonality, trends, and lags. Use LSTMs or Prophet for more advanced time-series forecasting.
12. Experimentation & A/B Testing
Experiment Design: Learn how to set up and analyze controlled experiments.
A/B Testing: Statistical techniques for comparing groups & measuring the impact of changes.
ENJOY LEARNING ๐๐
#datascience
โค10
Essential Python and SQL topics for data analysts ๐๐
Python Topics:
1. Data Structures
- Lists, Tuples, and Dictionaries
- NumPy Arrays for numerical data
2. Data Manipulation
- Pandas DataFrames for structured data
- Data Cleaning and Preprocessing techniques
- Data Transformation and Reshaping
3. Data Visualization
- Matplotlib for basic plotting
- Seaborn for statistical visualizations
- Plotly for interactive charts
4. Statistical Analysis
- Descriptive Statistics
- Hypothesis Testing
- Regression Analysis
5. Machine Learning
- Scikit-Learn for machine learning models
- Model Building, Training, and Evaluation
- Feature Engineering and Selection
6. Time Series Analysis
- Handling Time Series Data
- Time Series Forecasting
- Anomaly Detection
7. Python Fundamentals
- Control Flow (if statements, loops)
- Functions and Modular Code
- Exception Handling
- File
SQL Topics:
1. SQL Basics
- SQL Syntax
- SELECT Queries
- Filters
2. Data Retrieval
- Aggregation Functions (SUM, AVG, COUNT)
- GROUP BY
3. Data Filtering
- WHERE Clause
- ORDER BY
4. Data Joins
- JOIN Operations
- Subqueries
5. Advanced SQL
- Window Functions
- Indexing
- Performance Optimization
6. Database Management
- Connecting to Databases
- SQLAlchemy
7. Database Design
- Data Types
- Normalization
Remember, it's highly likely that you won't know all these concepts from the start. Data analysis is a journey where the more you learn, the more you grow. Embrace the learning process, and your skills will continually evolve and expand. Keep up the great work!
Python Resources - https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
SQL Resources - https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Hope it helps :)
Python Topics:
1. Data Structures
- Lists, Tuples, and Dictionaries
- NumPy Arrays for numerical data
2. Data Manipulation
- Pandas DataFrames for structured data
- Data Cleaning and Preprocessing techniques
- Data Transformation and Reshaping
3. Data Visualization
- Matplotlib for basic plotting
- Seaborn for statistical visualizations
- Plotly for interactive charts
4. Statistical Analysis
- Descriptive Statistics
- Hypothesis Testing
- Regression Analysis
5. Machine Learning
- Scikit-Learn for machine learning models
- Model Building, Training, and Evaluation
- Feature Engineering and Selection
6. Time Series Analysis
- Handling Time Series Data
- Time Series Forecasting
- Anomaly Detection
7. Python Fundamentals
- Control Flow (if statements, loops)
- Functions and Modular Code
- Exception Handling
- File
SQL Topics:
1. SQL Basics
- SQL Syntax
- SELECT Queries
- Filters
2. Data Retrieval
- Aggregation Functions (SUM, AVG, COUNT)
- GROUP BY
3. Data Filtering
- WHERE Clause
- ORDER BY
4. Data Joins
- JOIN Operations
- Subqueries
5. Advanced SQL
- Window Functions
- Indexing
- Performance Optimization
6. Database Management
- Connecting to Databases
- SQLAlchemy
7. Database Design
- Data Types
- Normalization
Remember, it's highly likely that you won't know all these concepts from the start. Data analysis is a journey where the more you learn, the more you grow. Embrace the learning process, and your skills will continually evolve and expand. Keep up the great work!
Python Resources - https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
SQL Resources - https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Hope it helps :)
โค4
Complete step-by-step syllabus of #Excel for Data Analytics
Introduction to Excel for Data Analytics:
Overview of Excel's capabilities for data analysis
Introduction to Excel's interface: ribbons, worksheets, cells, etc.
Differences between Excel desktop version and Excel Online (web version)
Data Import and Preparation:
Importing data from various sources: CSV, text files, databases, web queries, etc.
Data cleaning and manipulation techniques: sorting, filtering, removing duplicates, etc.
Data types and formatting in Excel
Data validation and error handling
Data Analysis Techniques in Excel:
Basic formulas and functions: SUM, AVERAGE, COUNT, IF, VLOOKUP, etc.
Advanced functions for data analysis: INDEX-MATCH, SUMIFS, COUNTIFS, etc.
PivotTables and PivotCharts for summarizing and analyzing data
Advanced data analysis tools: Goal Seek, Solver, What-If Analysis, etc.
Data Visualization in Excel:
Creating basic charts: column, bar, line, pie, scatter, etc.
Formatting and customizing charts for better visualization
Using sparklines for visualizing trends in data
Creating interactive dashboards with slicers and timelines
Advanced Data Analysis Features:
Data modeling with Excel Tables and Relationships
Using Power Query for data transformation and cleaning
Introduction to Power Pivot for data modeling and DAX calculations
Advanced charting techniques: combination charts, waterfall charts, etc.
Statistical Analysis in Excel:
Descriptive statistics: mean, median, mode, standard deviation, etc.
Hypothesis testing: t-tests, chi-square tests, ANOVA, etc.
Regression analysis and correlation
Forecasting techniques: moving averages, exponential smoothing, etc.
Data Visualization Tools in Excel:
Introduction to Excel add-ins for enhanced visualization (e.g., Power Map, Power View)
Creating interactive reports with Excel add-ins
Introduction to Excel Data Model for handling large datasets
Real-world Projects and Case Studies:
Analyzing real-world datasets
Solving business problems with Excel
Portfolio development showcasing Excel skills
Free Resources: https://t.iss.one/excel_data
Hope this helps you ๐
Introduction to Excel for Data Analytics:
Overview of Excel's capabilities for data analysis
Introduction to Excel's interface: ribbons, worksheets, cells, etc.
Differences between Excel desktop version and Excel Online (web version)
Data Import and Preparation:
Importing data from various sources: CSV, text files, databases, web queries, etc.
Data cleaning and manipulation techniques: sorting, filtering, removing duplicates, etc.
Data types and formatting in Excel
Data validation and error handling
Data Analysis Techniques in Excel:
Basic formulas and functions: SUM, AVERAGE, COUNT, IF, VLOOKUP, etc.
Advanced functions for data analysis: INDEX-MATCH, SUMIFS, COUNTIFS, etc.
PivotTables and PivotCharts for summarizing and analyzing data
Advanced data analysis tools: Goal Seek, Solver, What-If Analysis, etc.
Data Visualization in Excel:
Creating basic charts: column, bar, line, pie, scatter, etc.
Formatting and customizing charts for better visualization
Using sparklines for visualizing trends in data
Creating interactive dashboards with slicers and timelines
Advanced Data Analysis Features:
Data modeling with Excel Tables and Relationships
Using Power Query for data transformation and cleaning
Introduction to Power Pivot for data modeling and DAX calculations
Advanced charting techniques: combination charts, waterfall charts, etc.
Statistical Analysis in Excel:
Descriptive statistics: mean, median, mode, standard deviation, etc.
Hypothesis testing: t-tests, chi-square tests, ANOVA, etc.
Regression analysis and correlation
Forecasting techniques: moving averages, exponential smoothing, etc.
Data Visualization Tools in Excel:
Introduction to Excel add-ins for enhanced visualization (e.g., Power Map, Power View)
Creating interactive reports with Excel add-ins
Introduction to Excel Data Model for handling large datasets
Real-world Projects and Case Studies:
Analyzing real-world datasets
Solving business problems with Excel
Portfolio development showcasing Excel skills
Free Resources: https://t.iss.one/excel_data
Hope this helps you ๐
โค5๐ฅฐ1๐1
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SQL can be simpleโif you learn it the smart way..
If youโre aiming to become a data analyst, mastering SQL is non-negotiable.
Hereโs a smart roadmap to ace it:
1. Basics First: Understand data types, simple queries (SELECT, FROM, WHERE). Master basic filtering.
2. Joins & Relationships: Dive into INNER, LEFT, RIGHT joins. Practice combining tables to extract meaningful insights.
3. Aggregations & Functions: Get comfortable with COUNT, SUM, AVG, MAX, GROUP BY, and HAVING clauses. These are essential for summarizing data.
4. Subqueries & Nested Queries: Learn how to query within queries. This is powerful for handling complex datasets.
5. Window Functions: Explore ranking, cumulative sums, and sliding windows to work with running totals and moving averages.
6. Optimization: Study indexing and query optimization for faster, more efficient queries.
7. Real-World Scenarios: Apply your SQL knowledge to solve real-world business problems.
The journey may seem tough, but each step sharpens your skills and brings you closer to data analysis excellence. Stay consistent, practice regularly, and let SQL become your superpower! ๐ช
Here you can find essential SQL Interview Resources๐
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Hope it helps :)
If youโre aiming to become a data analyst, mastering SQL is non-negotiable.
Hereโs a smart roadmap to ace it:
1. Basics First: Understand data types, simple queries (SELECT, FROM, WHERE). Master basic filtering.
2. Joins & Relationships: Dive into INNER, LEFT, RIGHT joins. Practice combining tables to extract meaningful insights.
3. Aggregations & Functions: Get comfortable with COUNT, SUM, AVG, MAX, GROUP BY, and HAVING clauses. These are essential for summarizing data.
4. Subqueries & Nested Queries: Learn how to query within queries. This is powerful for handling complex datasets.
5. Window Functions: Explore ranking, cumulative sums, and sliding windows to work with running totals and moving averages.
6. Optimization: Study indexing and query optimization for faster, more efficient queries.
7. Real-World Scenarios: Apply your SQL knowledge to solve real-world business problems.
The journey may seem tough, but each step sharpens your skills and brings you closer to data analysis excellence. Stay consistent, practice regularly, and let SQL become your superpower! ๐ช
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โค10
Quick SQL functions cheat sheet for beginners
Aggregate Functions
COUNT(*): Counts rows.
SUM(column): Total sum.
AVG(column): Average value.
MAX(column): Maximum value.
MIN(column): Minimum value.
String Functions
CONCAT(a, b, โฆ): Concatenates strings.
SUBSTRING(s, start, length): Extracts part of a string.
UPPER(s) / LOWER(s): Converts string case.
TRIM(s): Removes leading/trailing spaces.
Date & Time Functions
CURRENT_DATE / CURRENT_TIME / CURRENT_TIMESTAMP: Current date/time.
EXTRACT(unit FROM date): Retrieves a date part (e.g., year, month).
DATE_ADD(date, INTERVAL n unit): Adds an interval to a date.
Numeric Functions
ROUND(num, decimals): Rounds to a specified decimal.
CEIL(num) / FLOOR(num): Rounds up/down.
ABS(num): Absolute value.
MOD(a, b): Returns the remainder.
Control Flow Functions
CASE: Conditional logic.
COALESCE(val1, val2, โฆ): Returns the first non-null value.
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#dataanalytics
Aggregate Functions
COUNT(*): Counts rows.
SUM(column): Total sum.
AVG(column): Average value.
MAX(column): Maximum value.
MIN(column): Minimum value.
String Functions
CONCAT(a, b, โฆ): Concatenates strings.
SUBSTRING(s, start, length): Extracts part of a string.
UPPER(s) / LOWER(s): Converts string case.
TRIM(s): Removes leading/trailing spaces.
Date & Time Functions
CURRENT_DATE / CURRENT_TIME / CURRENT_TIMESTAMP: Current date/time.
EXTRACT(unit FROM date): Retrieves a date part (e.g., year, month).
DATE_ADD(date, INTERVAL n unit): Adds an interval to a date.
Numeric Functions
ROUND(num, decimals): Rounds to a specified decimal.
CEIL(num) / FLOOR(num): Rounds up/down.
ABS(num): Absolute value.
MOD(a, b): Returns the remainder.
Control Flow Functions
CASE: Conditional logic.
COALESCE(val1, val2, โฆ): Returns the first non-null value.
Like for more free Cheatsheets โค๏ธ
Share with credits: https://t.iss.one/sqlspecialist
Hope it helps :)
#dataanalytics
โค14
SQL Interview Questions with Answers
1. How to change a table name in SQL?
This is the command to change a table name in SQL:
ALTER TABLE table_name
RENAME TO new_table_name;
We will start off by giving the keywords ALTER TABLE, then we will follow it up by giving the original name of the table, after that, we will give in the keywords RENAME TO and finally, we will give the new table name.
2. How to use LIKE in SQL?
The LIKE operator checks if an attribute value matches a given string pattern. Here is an example of LIKE operator
SELECT * FROM employees WHERE first_name like โStevenโ;
With this command, we will be able to extract all the records where the first name is like โStevenโ.
3. If we drop a table, does it also drop related objects like constraints, indexes, columns, default, views and sorted procedures?
Yes, SQL server drops all related objects, which exists inside a table like constraints, indexes, columns, defaults etc. But dropping a table will not drop views and sorted procedures as they exist outside the table.
4. Explain SQL Constraints.
SQL Constraints are used to specify the rules of data type in a table. They can be specified while creating and altering the table. The following are the constraints in SQL: NOT NULL CHECK DEFAULT UNIQUE PRIMARY KEY FOREIGN KEY
React โค๏ธ for more
1. How to change a table name in SQL?
This is the command to change a table name in SQL:
ALTER TABLE table_name
RENAME TO new_table_name;
We will start off by giving the keywords ALTER TABLE, then we will follow it up by giving the original name of the table, after that, we will give in the keywords RENAME TO and finally, we will give the new table name.
2. How to use LIKE in SQL?
The LIKE operator checks if an attribute value matches a given string pattern. Here is an example of LIKE operator
SELECT * FROM employees WHERE first_name like โStevenโ;
With this command, we will be able to extract all the records where the first name is like โStevenโ.
3. If we drop a table, does it also drop related objects like constraints, indexes, columns, default, views and sorted procedures?
Yes, SQL server drops all related objects, which exists inside a table like constraints, indexes, columns, defaults etc. But dropping a table will not drop views and sorted procedures as they exist outside the table.
4. Explain SQL Constraints.
SQL Constraints are used to specify the rules of data type in a table. They can be specified while creating and altering the table. The following are the constraints in SQL: NOT NULL CHECK DEFAULT UNIQUE PRIMARY KEY FOREIGN KEY
React โค๏ธ for more
โค8๐2
๐ Excel vs SQL vs Python (Pandas):
1๏ธโฃ Filtering Data
โณ Excel: =FILTER(A2:D100, B2:B100>50) (Excel 365 users)
โณ SQL: SELECT * FROM table WHERE column > 50;
โณ Python: df_filtered = df[df['column'] > 50]
2๏ธโฃ Sorting Data
โณ Excel: Data โ Sort (or =SORT(A2:A100, 1, TRUE))
โณ SQL: SELECT * FROM table ORDER BY column ASC;
โณ Python: df_sorted = df.sort_values(by="column")
3๏ธโฃ Counting Rows
โณ Excel: =COUNTA(A:A)
โณ SQL: SELECT COUNT(*) FROM table;
โณ Python: row_count = len(df)
4๏ธโฃ Removing Duplicates
โณ Excel: Data โ Remove Duplicates
โณ SQL: SELECT DISTINCT * FROM table;
โณ Python: df_unique = df.drop_duplicates()
5๏ธโฃ Joining Tables
โณ Excel: Power Query โ Merge Queries (or VLOOKUP/XLOOKUP)
โณ SQL: SELECT * FROM table1 JOIN table2 ON table1.id = table2.id;
โณ Python: df_merged = pd.merge(df1, df2, on="id")
6๏ธโฃ Ranking Data
โณ Excel: =RANK.EQ(A2, $A$2:$A$100)
โณ SQL: SELECT column, RANK() OVER (ORDER BY column DESC) AS rank FROM table;
โณ Python: df["rank"] = df["column"].rank(method="min", ascending=False)
7๏ธโฃ Moving Average Calculation
โณ Excel: =AVERAGE(B2:B4) (manually for rolling window)
โณ SQL: SELECT date, AVG(value) OVER (ORDER BY date ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS moving_avg FROM table;
โณ Python: df["moving_avg"] = df["value"].rolling(window=3).mean()
8๏ธโฃ Running Total
โณ Excel: =SUM($B$2:B2) (drag down)
โณ SQL: SELECT date, SUM(value) OVER (ORDER BY date) AS running_total FROM table;
โณ Python: df["running_total"] = df["value"].cumsum()
1๏ธโฃ Filtering Data
โณ Excel: =FILTER(A2:D100, B2:B100>50) (Excel 365 users)
โณ SQL: SELECT * FROM table WHERE column > 50;
โณ Python: df_filtered = df[df['column'] > 50]
2๏ธโฃ Sorting Data
โณ Excel: Data โ Sort (or =SORT(A2:A100, 1, TRUE))
โณ SQL: SELECT * FROM table ORDER BY column ASC;
โณ Python: df_sorted = df.sort_values(by="column")
3๏ธโฃ Counting Rows
โณ Excel: =COUNTA(A:A)
โณ SQL: SELECT COUNT(*) FROM table;
โณ Python: row_count = len(df)
4๏ธโฃ Removing Duplicates
โณ Excel: Data โ Remove Duplicates
โณ SQL: SELECT DISTINCT * FROM table;
โณ Python: df_unique = df.drop_duplicates()
5๏ธโฃ Joining Tables
โณ Excel: Power Query โ Merge Queries (or VLOOKUP/XLOOKUP)
โณ SQL: SELECT * FROM table1 JOIN table2 ON table1.id = table2.id;
โณ Python: df_merged = pd.merge(df1, df2, on="id")
6๏ธโฃ Ranking Data
โณ Excel: =RANK.EQ(A2, $A$2:$A$100)
โณ SQL: SELECT column, RANK() OVER (ORDER BY column DESC) AS rank FROM table;
โณ Python: df["rank"] = df["column"].rank(method="min", ascending=False)
7๏ธโฃ Moving Average Calculation
โณ Excel: =AVERAGE(B2:B4) (manually for rolling window)
โณ SQL: SELECT date, AVG(value) OVER (ORDER BY date ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS moving_avg FROM table;
โณ Python: df["moving_avg"] = df["value"].rolling(window=3).mean()
8๏ธโฃ Running Total
โณ Excel: =SUM($B$2:B2) (drag down)
โณ SQL: SELECT date, SUM(value) OVER (ORDER BY date) AS running_total FROM table;
โณ Python: df["running_total"] = df["value"].cumsum()
โค8๐1
9 tips to get started with Data Analysis:
Learn Excel, SQL, and a programming language (Python or R)
Understand basic statistics and probability
Practice with real-world datasets (Kaggle, Data.gov)
Clean and preprocess data effectively
Visualize data using charts and graphs
Ask the right questions before diving into data
Use libraries like Pandas, NumPy, and Matplotlib
Focus on storytelling with data insights
Build small projects to apply what you learn
Data Science & Machine Learning Resources: https://whatsapp.com/channel/0029Va8v3eo1NCrQfGMseL2D
ENJOY LEARNING ๐๐
Learn Excel, SQL, and a programming language (Python or R)
Understand basic statistics and probability
Practice with real-world datasets (Kaggle, Data.gov)
Clean and preprocess data effectively
Visualize data using charts and graphs
Ask the right questions before diving into data
Use libraries like Pandas, NumPy, and Matplotlib
Focus on storytelling with data insights
Build small projects to apply what you learn
Data Science & Machine Learning Resources: https://whatsapp.com/channel/0029Va8v3eo1NCrQfGMseL2D
ENJOY LEARNING ๐๐
โค5
Commonly used Power BI DAX functions:
DATE AND TIME FUNCTIONS:
-
-
-
AGGREGATE FUNCTIONS:
-
-
-
-
-
-
-
FILTER FUNCTIONS:
-
-
-
-
TIME INTELLIGENCE FUNCTIONS:
-
-
-
-
-
TEXT FUNCTIONS:
-
-
-
INFORMATION FUNCTIONS:
-
-
-
LOGICAL FUNCTIONS:
-
-
-
RELATIONSHIP FUNCTIONS:
-
-
-
Remember, DAX is more about logic than the formulas.
DATE AND TIME FUNCTIONS:
-
CALENDAR-
DATEDIFF-
TODAY, DAY, MONTH, QUARTER, YEARAGGREGATE FUNCTIONS:
-
SUM, SUMX, PRODUCT-
AVERAGE-
MIN, MAX-
COUNT-
COUNTROWS-
COUNTBLANK-
DISTINCTCOUNTFILTER FUNCTIONS:
-
CALCULATE-
FILTER-
ALL, ALLEXCEPT, ALLSELECTED, REMOVEFILTERS-
SELECTEDVALUETIME INTELLIGENCE FUNCTIONS:
-
DATESBETWEEN-
DATESMTD, DATESQTD, DATESYTD-
SAMEPERIODLASTYEAR-
PARALLELPERIOD-
TOTALMTD, TOTALQTD, TOTALYTDTEXT FUNCTIONS:
-
CONCATENATE-
FORMAT-
LEN, LEFT, RIGHTINFORMATION FUNCTIONS:
-
HASONEVALUE, HASONEFILTER-
ISBLANK, ISERROR, ISEMPTY-
CONTAINSLOGICAL FUNCTIONS:
-
AND, OR, IF, NOT-
TRUE, FALSE-
SWITCHRELATIONSHIP FUNCTIONS:
-
RELATED-
USERRELATIONSHIP-
RELATEDTABLERemember, DAX is more about logic than the formulas.
โค5
Everyone thinks being a great data analyst is about advanced algorithms and complex dashboards.
But real data excellence comes from methodical habits that build trust and deliver real insights.
Here are 20 signs of a truly effective analyst ๐
โ They document every step of their analysis
โ Clear notes make their work reproducible and trustworthy.
โ They check data quality before the analysis begins
โ Garbage in = garbage out. Always validate first.
โ They use version control religiously
โ Every code change is tracked. Nothing gets lost.
โ They explore data thoroughly before diving in
โ Understanding context prevents costly misinterpretations.
โ They create automated scripts for repetitive tasks
โ Efficiency isnโt a luxuryโitโs a necessity.
โ They maintain a reusable code library
โ Smart analysts never solve the same problem twice.
โ They test assumptions with multiple validation methods
โ One test isnโt enough; they triangulate confidence.
โ They organize project files logically
โ Their work is navigable by anyone, not just themselves.
โ They seek peer reviews on critical work
โ Fresh eyes catch blind spots.
โ They continuously absorb industry knowledge
โ Learning never stops. Trends change too quickly.
โ They prioritize business-impacting projects
โ Every analysis must drive real decisions.
โ They explain complex findings simply
โ Technical brilliance is useless without clarity.
โ They write readable, well-commented code
โ Their work is accessible to others, long after they're gone.
โ They maintain robust backup systems
โ Data loss is never an option.
โ They learn from analytical mistakes
โ Errors become stepping stones, not roadblocks.
โ They build strong stakeholder relationships
โ Data is only valuable when people use it.
โ They break complex projects into manageable chunks
โ Progress happens through disciplined, incremental work.
โ They handle sensitive data with proper security
โ Compliance isnโt optionalโitโs foundational.
โ They create visualizations that tell clear stories
โ A chart without a narrative is just decoration.
โ They actively seek evidence against their conclusions
โ Confirmation bias is their biggest enemy.
The best analysts arenโt the ones with the most toolsโtheyโre the ones with the most rigorous practices.
But real data excellence comes from methodical habits that build trust and deliver real insights.
Here are 20 signs of a truly effective analyst ๐
โ They document every step of their analysis
โ Clear notes make their work reproducible and trustworthy.
โ They check data quality before the analysis begins
โ Garbage in = garbage out. Always validate first.
โ They use version control religiously
โ Every code change is tracked. Nothing gets lost.
โ They explore data thoroughly before diving in
โ Understanding context prevents costly misinterpretations.
โ They create automated scripts for repetitive tasks
โ Efficiency isnโt a luxuryโitโs a necessity.
โ They maintain a reusable code library
โ Smart analysts never solve the same problem twice.
โ They test assumptions with multiple validation methods
โ One test isnโt enough; they triangulate confidence.
โ They organize project files logically
โ Their work is navigable by anyone, not just themselves.
โ They seek peer reviews on critical work
โ Fresh eyes catch blind spots.
โ They continuously absorb industry knowledge
โ Learning never stops. Trends change too quickly.
โ They prioritize business-impacting projects
โ Every analysis must drive real decisions.
โ They explain complex findings simply
โ Technical brilliance is useless without clarity.
โ They write readable, well-commented code
โ Their work is accessible to others, long after they're gone.
โ They maintain robust backup systems
โ Data loss is never an option.
โ They learn from analytical mistakes
โ Errors become stepping stones, not roadblocks.
โ They build strong stakeholder relationships
โ Data is only valuable when people use it.
โ They break complex projects into manageable chunks
โ Progress happens through disciplined, incremental work.
โ They handle sensitive data with proper security
โ Compliance isnโt optionalโitโs foundational.
โ They create visualizations that tell clear stories
โ A chart without a narrative is just decoration.
โ They actively seek evidence against their conclusions
โ Confirmation bias is their biggest enemy.
The best analysts arenโt the ones with the most toolsโtheyโre the ones with the most rigorous practices.
โค11
If youโre a Data Analyst, chances are you use ๐๐๐ every single day. And if youโre preparing for interviews, youโve probably realized that it's not just about writing queries it's about writing smart, efficient, and scalable ones.
1. ๐๐ซ๐๐๐ค ๐๐ญ ๐๐จ๐ฐ๐ง ๐ฐ๐ข๐ญ๐ก ๐๐๐๐ฌ (๐๐จ๐ฆ๐ฆ๐จ๐ง ๐๐๐๐ฅ๐ ๐๐ฑ๐ฉ๐ซ๐๐ฌ๐ฌ๐ข๐จ๐ง๐ฌ)
Ever worked on a query that became an unreadable monster? CTEs let you break that down into logical steps. You can treat them like temporary views โ great for simplifying logic and improving collaboration across your team.
2. ๐๐ฌ๐ ๐๐ข๐ง๐๐จ๐ฐ ๐ ๐ฎ๐ง๐๐ญ๐ข๐จ๐ง๐ฌ
Forget the mess of subqueries. With functions like ROW_NUMBER(), RANK(), LEAD() and LAG(), you can compare rows, rank items, or calculate running totals โ all within the same query. Total
3. ๐๐ฎ๐๐ช๐ฎ๐๐ซ๐ข๐๐ฌ (๐๐๐ฌ๐ญ๐๐ ๐๐ฎ๐๐ซ๐ข๐๐ฌ)
Yes, they're old school, but nested subqueries are still powerful. Use them when you want to filter based on results of another query or isolate logic step-by-step before joining with the big picture.
4. ๐๐ง๐๐๐ฑ๐๐ฌ & ๐๐ฎ๐๐ซ๐ฒ ๐๐ฉ๐ญ๐ข๐ฆ๐ข๐ณ๐๐ญ๐ข๐จ๐ง
Query taking forever? Look at your indexes. Index the columns you use in JOINs, WHERE, and GROUP BY. Even basic knowledge of how the SQL engine reads data can take your skills up a notch.
5. ๐๐จ๐ข๐ง๐ฌ ๐ฏ๐ฌ. ๐๐ฎ๐๐ช๐ฎ๐๐ซ๐ข๐๐ฌ
Joins are usually faster and better for combining large datasets. Subqueries, on the other hand, are cleaner when doing one-off filters or smaller operations. Choose wisely based on the context.
6. ๐๐๐๐ ๐๐ญ๐๐ญ๐๐ฆ๐๐ง๐ญ๐ฌ:
Want to categorize or bucket data without creating a separate table? Use CASE. Itโs ideal for conditional logic, custom labels, and grouping in a single query.
7. ๐๐ ๐ ๐ซ๐๐ ๐๐ญ๐ข๐จ๐ง๐ฌ & ๐๐๐๐๐ ๐๐
Most analytics questions start with "how many", "whatโs the average", or "which is the highest?". SUM(), COUNT(), AVG(), etc., and pair them with GROUP BY to drive insights that matter.
8. ๐๐๐ญ๐๐ฌ ๐๐ซ๐ ๐๐ฅ๐ฐ๐๐ฒ๐ฌ ๐๐ซ๐ข๐๐ค๐ฒ
Time-based analysis is everywhere: trends, cohorts, seasonality, etc. Get familiar with functions like DATEADD, DATEDIFF, DATE_TRUNC, and DATEPART to work confidently with time series data.
9. ๐๐๐ฅ๐-๐๐จ๐ข๐ง๐ฌ & ๐๐๐๐ฎ๐ซ๐ฌ๐ข๐ฏ๐ ๐๐ฎ๐๐ซ๐ข๐๐ฌ ๐๐จ๐ซ ๐๐ข๐๐ซ๐๐ซ๐๐ก๐ข๐๐ฌ
Whether it's org charts or product categories, not all data is flat. Learn how to join a table to itself or use recursive CTEs to navigate parent-child relationships effectively.
You donโt need to memorize 100 functions. You need to understand 10 really well and apply them smartly. These are the concepts I keep going back to not just in interviews, but in the real world where clarity, performance, and logic matter most.
1. ๐๐ซ๐๐๐ค ๐๐ญ ๐๐จ๐ฐ๐ง ๐ฐ๐ข๐ญ๐ก ๐๐๐๐ฌ (๐๐จ๐ฆ๐ฆ๐จ๐ง ๐๐๐๐ฅ๐ ๐๐ฑ๐ฉ๐ซ๐๐ฌ๐ฌ๐ข๐จ๐ง๐ฌ)
Ever worked on a query that became an unreadable monster? CTEs let you break that down into logical steps. You can treat them like temporary views โ great for simplifying logic and improving collaboration across your team.
2. ๐๐ฌ๐ ๐๐ข๐ง๐๐จ๐ฐ ๐ ๐ฎ๐ง๐๐ญ๐ข๐จ๐ง๐ฌ
Forget the mess of subqueries. With functions like ROW_NUMBER(), RANK(), LEAD() and LAG(), you can compare rows, rank items, or calculate running totals โ all within the same query. Total
3. ๐๐ฎ๐๐ช๐ฎ๐๐ซ๐ข๐๐ฌ (๐๐๐ฌ๐ญ๐๐ ๐๐ฎ๐๐ซ๐ข๐๐ฌ)
Yes, they're old school, but nested subqueries are still powerful. Use them when you want to filter based on results of another query or isolate logic step-by-step before joining with the big picture.
4. ๐๐ง๐๐๐ฑ๐๐ฌ & ๐๐ฎ๐๐ซ๐ฒ ๐๐ฉ๐ญ๐ข๐ฆ๐ข๐ณ๐๐ญ๐ข๐จ๐ง
Query taking forever? Look at your indexes. Index the columns you use in JOINs, WHERE, and GROUP BY. Even basic knowledge of how the SQL engine reads data can take your skills up a notch.
5. ๐๐จ๐ข๐ง๐ฌ ๐ฏ๐ฌ. ๐๐ฎ๐๐ช๐ฎ๐๐ซ๐ข๐๐ฌ
Joins are usually faster and better for combining large datasets. Subqueries, on the other hand, are cleaner when doing one-off filters or smaller operations. Choose wisely based on the context.
6. ๐๐๐๐ ๐๐ญ๐๐ญ๐๐ฆ๐๐ง๐ญ๐ฌ:
Want to categorize or bucket data without creating a separate table? Use CASE. Itโs ideal for conditional logic, custom labels, and grouping in a single query.
7. ๐๐ ๐ ๐ซ๐๐ ๐๐ญ๐ข๐จ๐ง๐ฌ & ๐๐๐๐๐ ๐๐
Most analytics questions start with "how many", "whatโs the average", or "which is the highest?". SUM(), COUNT(), AVG(), etc., and pair them with GROUP BY to drive insights that matter.
8. ๐๐๐ญ๐๐ฌ ๐๐ซ๐ ๐๐ฅ๐ฐ๐๐ฒ๐ฌ ๐๐ซ๐ข๐๐ค๐ฒ
Time-based analysis is everywhere: trends, cohorts, seasonality, etc. Get familiar with functions like DATEADD, DATEDIFF, DATE_TRUNC, and DATEPART to work confidently with time series data.
9. ๐๐๐ฅ๐-๐๐จ๐ข๐ง๐ฌ & ๐๐๐๐ฎ๐ซ๐ฌ๐ข๐ฏ๐ ๐๐ฎ๐๐ซ๐ข๐๐ฌ ๐๐จ๐ซ ๐๐ข๐๐ซ๐๐ซ๐๐ก๐ข๐๐ฌ
Whether it's org charts or product categories, not all data is flat. Learn how to join a table to itself or use recursive CTEs to navigate parent-child relationships effectively.
You donโt need to memorize 100 functions. You need to understand 10 really well and apply them smartly. These are the concepts I keep going back to not just in interviews, but in the real world where clarity, performance, and logic matter most.
โค6๐6
Essential Skills Excel for Data Analysts ๐
1๏ธโฃ Data Cleaning & Transformation
Remove Duplicates โ Ensure unique records.
Find & Replace โ Quick data modifications.
Text Functions โ TRIM, LEN, LEFT, RIGHT, MID, PROPER.
Data Validation โ Restrict input values.
2๏ธโฃ Data Analysis & Manipulation
Sorting & Filtering โ Organize and extract key insights.
Conditional Formatting โ Highlight trends, outliers.
Pivot Tables โ Summarize large datasets efficiently.
Power Query โ Automate data transformation.
3๏ธโฃ Essential Formulas & Functions
Lookup Functions โ VLOOKUP, HLOOKUP, XLOOKUP, INDEX-MATCH.
Logical Functions โ IF, AND, OR, IFERROR, IFS.
Aggregation Functions โ SUM, AVERAGE, MIN, MAX, COUNT, COUNTA.
Text Functions โ CONCATENATE, TEXTJOIN, SUBSTITUTE.
4๏ธโฃ Data Visualization
Charts & Graphs โ Bar, Line, Pie, Scatter, Histogram.
Sparklines โ Miniature charts inside cells.
Conditional Formatting โ Color scales, data bars.
Dashboard Creation โ Interactive and dynamic reports.
5๏ธโฃ Advanced Excel Techniques
Array Formulas โ Dynamic calculations with multiple values.
Power Pivot & DAX โ Advanced data modeling.
What-If Analysis โ Goal Seek, Scenario Manager.
Macros & VBA โ Automate repetitive tasks.
6๏ธโฃ Data Import & Export
CSV & TXT Files โ Import and clean raw data.
Power Query โ Connect to databases, web sources.
Exporting Reports โ PDF, CSV, Excel formats.
Here you can find some free Excel books & useful resources: https://t.iss.one/excel_data
Hope it helps :)
#dataanalyst
1๏ธโฃ Data Cleaning & Transformation
Remove Duplicates โ Ensure unique records.
Find & Replace โ Quick data modifications.
Text Functions โ TRIM, LEN, LEFT, RIGHT, MID, PROPER.
Data Validation โ Restrict input values.
2๏ธโฃ Data Analysis & Manipulation
Sorting & Filtering โ Organize and extract key insights.
Conditional Formatting โ Highlight trends, outliers.
Pivot Tables โ Summarize large datasets efficiently.
Power Query โ Automate data transformation.
3๏ธโฃ Essential Formulas & Functions
Lookup Functions โ VLOOKUP, HLOOKUP, XLOOKUP, INDEX-MATCH.
Logical Functions โ IF, AND, OR, IFERROR, IFS.
Aggregation Functions โ SUM, AVERAGE, MIN, MAX, COUNT, COUNTA.
Text Functions โ CONCATENATE, TEXTJOIN, SUBSTITUTE.
4๏ธโฃ Data Visualization
Charts & Graphs โ Bar, Line, Pie, Scatter, Histogram.
Sparklines โ Miniature charts inside cells.
Conditional Formatting โ Color scales, data bars.
Dashboard Creation โ Interactive and dynamic reports.
5๏ธโฃ Advanced Excel Techniques
Array Formulas โ Dynamic calculations with multiple values.
Power Pivot & DAX โ Advanced data modeling.
What-If Analysis โ Goal Seek, Scenario Manager.
Macros & VBA โ Automate repetitive tasks.
6๏ธโฃ Data Import & Export
CSV & TXT Files โ Import and clean raw data.
Power Query โ Connect to databases, web sources.
Exporting Reports โ PDF, CSV, Excel formats.
Here you can find some free Excel books & useful resources: https://t.iss.one/excel_data
Hope it helps :)
#dataanalyst
โค10
๐๐จ๐ฐ ๐ญ๐จ ๐๐ซ๐๐ฉ๐๐ซ๐ ๐ญ๐จ ๐๐๐๐จ๐ฆ๐ ๐ ๐๐๐ญ๐ ๐๐ง๐๐ฅ๐ฒ๐ฌ๐ญ
๐. ๐๐ฑ๐๐๐ฅ- Learn formulas, Pivot tables, Lookup, VBA Macros.
๐. ๐๐๐- Joins, Windows, CTE is the most important
๐. ๐๐จ๐ฐ๐๐ซ ๐๐- Power Query Editor(PQE), DAX, MCode, RLS
๐. ๐๐ฒ๐ญ๐ก๐จ๐ง- Basics & Libraries(mainly pandas, numpy, matplotlib and seaborn libraries)
5. Practice SQL and Python questions on platforms like ๐๐๐๐ค๐๐ซ๐๐๐ง๐ค or ๐๐๐๐๐ก๐จ๐จ๐ฅ๐ฌ.
6. Know the basics of descriptive statistics(mean, median, mode, Probability, normal, binomial, Poisson distributions etc).
7. Learn to use ๐๐/๐๐จ๐ฉ๐ข๐ฅ๐จ๐ญ ๐ญ๐จ๐จ๐ฅ๐ฌ like GitHub Copilot or Power BI's AI features to automate tasks, generate insights, and improve your projects(Most demanding in Companies now)
8. Get hands-on experience with one cloud platform: ๐๐ณ๐ฎ๐ซ๐, ๐๐๐, ๐จ๐ซ ๐๐๐
9. Work on at least two end-to-end projects.
10. Prepare an ATS-friendly resume and start applying for jobs.
11. Prepare for interviews by going through common interview questions on Google and YouTube.
I have curated top-notch Data Analytics Resources ๐๐
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope this helps you ๐
๐. ๐๐ฑ๐๐๐ฅ- Learn formulas, Pivot tables, Lookup, VBA Macros.
๐. ๐๐๐- Joins, Windows, CTE is the most important
๐. ๐๐จ๐ฐ๐๐ซ ๐๐- Power Query Editor(PQE), DAX, MCode, RLS
๐. ๐๐ฒ๐ญ๐ก๐จ๐ง- Basics & Libraries(mainly pandas, numpy, matplotlib and seaborn libraries)
5. Practice SQL and Python questions on platforms like ๐๐๐๐ค๐๐ซ๐๐๐ง๐ค or ๐๐๐๐๐ก๐จ๐จ๐ฅ๐ฌ.
6. Know the basics of descriptive statistics(mean, median, mode, Probability, normal, binomial, Poisson distributions etc).
7. Learn to use ๐๐/๐๐จ๐ฉ๐ข๐ฅ๐จ๐ญ ๐ญ๐จ๐จ๐ฅ๐ฌ like GitHub Copilot or Power BI's AI features to automate tasks, generate insights, and improve your projects(Most demanding in Companies now)
8. Get hands-on experience with one cloud platform: ๐๐ณ๐ฎ๐ซ๐, ๐๐๐, ๐จ๐ซ ๐๐๐
9. Work on at least two end-to-end projects.
10. Prepare an ATS-friendly resume and start applying for jobs.
11. Prepare for interviews by going through common interview questions on Google and YouTube.
I have curated top-notch Data Analytics Resources ๐๐
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope this helps you ๐
โค6
Roadmap to become a Data Analyst:
๐ Learn Excel
โ๐ Learn SQL
โ๐ Learn Python
โ๐ Learn Power BI / Tableau
โ๐ Learn Statistics & Probability
โ๐ Learn Data Transformation
โ๐ Learn Machine Learning Basics
โ๐ Build Projects & Portfolio
โโ Apply for Job
React โค๏ธ for More ๐
๐ Learn Excel
โ๐ Learn SQL
โ๐ Learn Python
โ๐ Learn Power BI / Tableau
โ๐ Learn Statistics & Probability
โ๐ Learn Data Transformation
โ๐ Learn Machine Learning Basics
โ๐ Build Projects & Portfolio
โโ Apply for Job
React โค๏ธ for More ๐
โค21
Let's now understand the above Data Analyst Roadmap in detail: ๐ง โ๏ธ
1๏ธโฃ Learn Excel โญ๏ธ
The foundation of data analysis. Learn formulas, pivot tables, charts, VLOOKUP/XLOOKUP, and conditional formatting. It helps in quick data cleaning and presenting insights.
Excel Resources: https://whatsapp.com/channel/0029VaifY548qIzv0u1AHz3i
2๏ธโฃ Learn SQL ๐ป
Essential for working with databases. Focus on
SQL Resources: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
3๏ธโฃ Learn Python ๐ฑ
A powerful tool for data manipulation and automation. Master libraries like
Python Resources: https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
4๏ธโฃ Learn Power BI / Tableau ๐
These tools help create interactive dashboards and visual reports. Learn how to import data, create filters, use DAX (Power BI), and design clear visualizations.
Power BI Resources: https://whatsapp.com/channel/0029Vai1xKf1dAvuk6s1v22c
5๏ธโฃ Learn Statistics & Probability ๐
Know about descriptive stats (mean, median, mode), inferential stats, distributions, hypothesis testing, and correlation. Vital for making sense of data trends.
Statistics Resources: https://whatsapp.com/channel/0029Vat3Dc4KAwEcfFbNnZ3O
6๏ธโฃ Learn Data Transformation ๐
Learn how to clean, shape, and prepare data for analysis. Use Python (
Data Cleaning: https://whatsapp.com/channel/0029VarxgFqATRSpdUeHUA27
7๏ธโฃ Learn Machine Learning ๐ง
Understand basic concepts like regression, classification, clustering, and decision trees. You donโt need to be an ML expert, just grasp how models work and when to use them.
Machine Learning: https://whatsapp.com/channel/0029VawtYcJ1iUxcMQoEuP0O
8๏ธโฃ Build Projects & Portfolio ๐น
Apply what youโve learned to real datasetsโlike sales analysis, churn prediction, or dashboard creation. Showcase your work on GitHub or a personal website.
Data Analytics Projects: https://whatsapp.com/channel/0029VbAbnvPLSmbeFYNdNA29
9๏ธโฃ Apply for Jobs ๐ผ
With your skills and portfolio in place, start applying for data analyst roles. Tailor your resume using keywords from job descriptions and prepare to answer SQL and Excel tasks in interviews.
Jobs & Internship Opportunities: https://whatsapp.com/channel/0029VaI5CV93AzNUiZ5Tt226
Share with credits: https://t.iss.one/sqlspecialist
Double Tap โฅ๏ธ for more
1๏ธโฃ Learn Excel โญ๏ธ
The foundation of data analysis. Learn formulas, pivot tables, charts, VLOOKUP/XLOOKUP, and conditional formatting. It helps in quick data cleaning and presenting insights.
Excel Resources: https://whatsapp.com/channel/0029VaifY548qIzv0u1AHz3i
2๏ธโฃ Learn SQL ๐ป
Essential for working with databases. Focus on
SELECT, JOIN, GROUP BY, WHERE, and subqueries to extract and manipulate data from relational databases.SQL Resources: https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
3๏ธโฃ Learn Python ๐ฑ
A powerful tool for data manipulation and automation. Master libraries like
pandas, numpy, matplotlib, and seaborn for data cleaning and visualization.Python Resources: https://whatsapp.com/channel/0029VaiM08SDuMRaGKd9Wv0L
4๏ธโฃ Learn Power BI / Tableau ๐
These tools help create interactive dashboards and visual reports. Learn how to import data, create filters, use DAX (Power BI), and design clear visualizations.
Power BI Resources: https://whatsapp.com/channel/0029Vai1xKf1dAvuk6s1v22c
5๏ธโฃ Learn Statistics & Probability ๐
Know about descriptive stats (mean, median, mode), inferential stats, distributions, hypothesis testing, and correlation. Vital for making sense of data trends.
Statistics Resources: https://whatsapp.com/channel/0029Vat3Dc4KAwEcfFbNnZ3O
6๏ธโฃ Learn Data Transformation ๐
Learn how to clean, shape, and prepare data for analysis. Use Python (
pandas) or Power Query in Power BI, and understand ETL (Extract, Transform, Load) processes.Data Cleaning: https://whatsapp.com/channel/0029VarxgFqATRSpdUeHUA27
7๏ธโฃ Learn Machine Learning ๐ง
Understand basic concepts like regression, classification, clustering, and decision trees. You donโt need to be an ML expert, just grasp how models work and when to use them.
Machine Learning: https://whatsapp.com/channel/0029VawtYcJ1iUxcMQoEuP0O
8๏ธโฃ Build Projects & Portfolio ๐น
Apply what youโve learned to real datasetsโlike sales analysis, churn prediction, or dashboard creation. Showcase your work on GitHub or a personal website.
Data Analytics Projects: https://whatsapp.com/channel/0029VbAbnvPLSmbeFYNdNA29
9๏ธโฃ Apply for Jobs ๐ผ
With your skills and portfolio in place, start applying for data analyst roles. Tailor your resume using keywords from job descriptions and prepare to answer SQL and Excel tasks in interviews.
Jobs & Internship Opportunities: https://whatsapp.com/channel/0029VaI5CV93AzNUiZ5Tt226
Share with credits: https://t.iss.one/sqlspecialist
Double Tap โฅ๏ธ for more
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Top 10 Excel Interview Questions with Answers โ
1. Question: What is the difference between CONCATENATE and "&" in Excel?
Answer: CONCATENATE and "&" both combine text, but "&" is more concise. For example,
2. Question: How can you freeze rows and columns simultaneously in Excel?
Answer: Use the "Freeze Panes" option under the "View" tab. Select the cell below and to the right of the rows and columns you want to freeze, and then click on "Freeze Panes."
3. Question: Explain the VLOOKUP function and when would you use it?
Answer: VLOOKUP searches for a value in the first column of a range and returns a corresponding value in the same row from another column. It's useful for looking up information in a table based on a specific criteria.
4. Question: What is the purpose of the IFERROR function?
Answer: IFERROR is used to handle errors in Excel formulas. It returns a specified value if a formula results in an error, and the actual result if there's no error.
5. Question: How do you create a PivotTable, and what is its purpose?
Answer: To create a PivotTable, select your data, go to the "Insert" tab, and choose "PivotTable." It summarizes and analyzes data in a spreadsheet, allowing you to make sense of large datasets.
6. Question: Explain the difference between relative and absolute cell references.
Answer: Relative references change when you copy a formula to another cell, while absolute references stay fixed. Use a
7. Question: What is the purpose of the INDEX and MATCH functions?
Answer: INDEX returns a value in a specified range based on the row and column number, while MATCH searches for a value in a range and returns its relative position. Combined, they provide a flexible way to look up data.
8. Question: How can you find and remove duplicate values in Excel?
Answer: Use the "Remove Duplicates" feature under the "Data" tab. Select the range containing duplicates, go to "Data" -> "Remove Duplicates," and choose the columns to check for duplicates.
9. Question: Explain the difference between a workbook and a worksheet.
Answer: A workbook is the entire Excel file, while a worksheet is a single sheet within that file. Workbooks can contain multiple worksheets.
10. Question: What is the purpose of the COUNTIF function?
Answer: COUNTIF counts the number of cells within a range that meet a specified condition. For example,
Free Excel Resources: https://t.iss.one/excel_data
Hope it helpsโ
1. Question: What is the difference between CONCATENATE and "&" in Excel?
Answer: CONCATENATE and "&" both combine text, but "&" is more concise. For example,
=A1&B1 achieves the same result as =CONCATENATE(A1, B1).2. Question: How can you freeze rows and columns simultaneously in Excel?
Answer: Use the "Freeze Panes" option under the "View" tab. Select the cell below and to the right of the rows and columns you want to freeze, and then click on "Freeze Panes."
3. Question: Explain the VLOOKUP function and when would you use it?
Answer: VLOOKUP searches for a value in the first column of a range and returns a corresponding value in the same row from another column. It's useful for looking up information in a table based on a specific criteria.
4. Question: What is the purpose of the IFERROR function?
Answer: IFERROR is used to handle errors in Excel formulas. It returns a specified value if a formula results in an error, and the actual result if there's no error.
5. Question: How do you create a PivotTable, and what is its purpose?
Answer: To create a PivotTable, select your data, go to the "Insert" tab, and choose "PivotTable." It summarizes and analyzes data in a spreadsheet, allowing you to make sense of large datasets.
6. Question: Explain the difference between relative and absolute cell references.
Answer: Relative references change when you copy a formula to another cell, while absolute references stay fixed. Use a
$ symbol to make a reference absolute (e.g., $A$1).7. Question: What is the purpose of the INDEX and MATCH functions?
Answer: INDEX returns a value in a specified range based on the row and column number, while MATCH searches for a value in a range and returns its relative position. Combined, they provide a flexible way to look up data.
8. Question: How can you find and remove duplicate values in Excel?
Answer: Use the "Remove Duplicates" feature under the "Data" tab. Select the range containing duplicates, go to "Data" -> "Remove Duplicates," and choose the columns to check for duplicates.
9. Question: Explain the difference between a workbook and a worksheet.
Answer: A workbook is the entire Excel file, while a worksheet is a single sheet within that file. Workbooks can contain multiple worksheets.
10. Question: What is the purpose of the COUNTIF function?
Answer: COUNTIF counts the number of cells within a range that meet a specified condition. For example,
=COUNTIF(A1:A10, ">50") counts the cells in A1 to A10 that are greater than 50.Free Excel Resources: https://t.iss.one/excel_data
Hope it helps
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AI/ML roadmap
Topic: Mathematics
- Subtopic: Linear Algebra
- Vectors, Matrices, Eigenvalues and Eigenvectors
- Subtopic: Calculus
- Differentiation, Integration, Partial Derivatives
- Subtopic: Probability and Statistics
- Probability Theory, Random Variables, Statistical Inference
Topic: Programming
- Subtopic: Python
- Python Basics, Libraries like NumPy, Pandas, Matplotlib
Topic: Machine Learning
- Subtopic: Supervised Learning
- Linear Regression, Logistic Regression, Decision Trees
- Subtopic: Unsupervised Learning
- Clustering, Dimensionality Reduction[1](https://i.am.ai/roadmap)
- Subtopic: Neural Networks and Deep Learning
- Feedforward Neural Networks, Convolutional Neural Networks, Recurrent Neural Networks
Topic: Specializations
- Subtopic: Natural Language Processing
- Text Preprocessing, Topic Modeling, Word Embeddings
- Subtopic: Computer Vision
- Image Processing, Object Detection, Image Segmentation
- Subtopic: Reinforcement Learning
- Markov Decision Processes, Q-Learning, Policy Gradients
Join for more: https://t.iss.one/machinelearning_deeplearning
Topic: Mathematics
- Subtopic: Linear Algebra
- Vectors, Matrices, Eigenvalues and Eigenvectors
- Subtopic: Calculus
- Differentiation, Integration, Partial Derivatives
- Subtopic: Probability and Statistics
- Probability Theory, Random Variables, Statistical Inference
Topic: Programming
- Subtopic: Python
- Python Basics, Libraries like NumPy, Pandas, Matplotlib
Topic: Machine Learning
- Subtopic: Supervised Learning
- Linear Regression, Logistic Regression, Decision Trees
- Subtopic: Unsupervised Learning
- Clustering, Dimensionality Reduction[1](https://i.am.ai/roadmap)
- Subtopic: Neural Networks and Deep Learning
- Feedforward Neural Networks, Convolutional Neural Networks, Recurrent Neural Networks
Topic: Specializations
- Subtopic: Natural Language Processing
- Text Preprocessing, Topic Modeling, Word Embeddings
- Subtopic: Computer Vision
- Image Processing, Object Detection, Image Segmentation
- Subtopic: Reinforcement Learning
- Markov Decision Processes, Q-Learning, Policy Gradients
Join for more: https://t.iss.one/machinelearning_deeplearning
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Scenario based Interview Questions & Answers for Data Analyst
1. Scenario: You are working on a SQL database that stores customer information. The database has a table called "Orders" that contains order details. Your task is to write a SQL query to retrieve the total number of orders placed by each customer.
Question:
- Write a SQL query to find the total number of orders placed by each customer.
Expected Answer:
SELECT CustomerID, COUNT(*) AS TotalOrders
FROM Orders
GROUP BY CustomerID;
2. Scenario: You are working on a SQL database that stores employee information. The database has a table called "Employees" that contains employee details. Your task is to write a SQL query to retrieve the names of all employees who have been with the company for more than 5 years.
Question:
- Write a SQL query to find the names of employees who have been with the company for more than 5 years.
Expected Answer:
SELECT Name
FROM Employees
WHERE DATEDIFF(year, HireDate, GETDATE()) > 5;
Power BI Scenario-Based Questions
1. Scenario: You have been given a dataset in Power BI that contains sales data for a company. Your task is to create a report that shows the total sales by product category and region.
Expected Answer:
- Load the dataset into Power BI.
- Create relationships if necessary.
- Use the "Fields" pane to select the necessary fields (Product Category, Region, Sales).
- Drag these fields into the "Values" area of a new visualization (e.g., a table or bar chart).
- Use the "Filters" pane to filter data as needed.
- Format the visualization to enhance clarity and readability.
2. Scenario: You have been asked to create a Power BI dashboard that displays real-time stock prices for a set of companies. The stock prices are available through an API.
Expected Answer:
- Use Power BI Desktop to connect to the API.
- Go to "Get Data" > "Web" and enter the API URL.
- Configure the data refresh settings to ensure real-time updates (e.g., setting up a scheduled refresh or using DirectQuery if supported).
- Create visualizations using the imported data.
- Publish the report to the Power BI service and set up a data gateway if needed for continuous refresh.
3. Scenario: You have been given a Power BI report that contains multiple visualizations. The report is taking a long time to load and is impacting the performance of the application.
Expected Answer:
- Analyze the current performance using Performance Analyzer.
- Optimize data model by reducing the number of columns and rows, and removing unnecessary calculations.
- Use aggregated tables to pre-compute results.
- Simplify DAX calculations.
- Optimize visualizations by reducing the number of visuals per page and avoiding complex custom visuals.
- Ensure proper indexing on the data source.
Free SQL Resources: t.iss.one/mysqldata
Like if you need more similar content
Hope it helps :)
1. Scenario: You are working on a SQL database that stores customer information. The database has a table called "Orders" that contains order details. Your task is to write a SQL query to retrieve the total number of orders placed by each customer.
Question:
- Write a SQL query to find the total number of orders placed by each customer.
Expected Answer:
SELECT CustomerID, COUNT(*) AS TotalOrders
FROM Orders
GROUP BY CustomerID;
2. Scenario: You are working on a SQL database that stores employee information. The database has a table called "Employees" that contains employee details. Your task is to write a SQL query to retrieve the names of all employees who have been with the company for more than 5 years.
Question:
- Write a SQL query to find the names of employees who have been with the company for more than 5 years.
Expected Answer:
SELECT Name
FROM Employees
WHERE DATEDIFF(year, HireDate, GETDATE()) > 5;
Power BI Scenario-Based Questions
1. Scenario: You have been given a dataset in Power BI that contains sales data for a company. Your task is to create a report that shows the total sales by product category and region.
Expected Answer:
- Load the dataset into Power BI.
- Create relationships if necessary.
- Use the "Fields" pane to select the necessary fields (Product Category, Region, Sales).
- Drag these fields into the "Values" area of a new visualization (e.g., a table or bar chart).
- Use the "Filters" pane to filter data as needed.
- Format the visualization to enhance clarity and readability.
2. Scenario: You have been asked to create a Power BI dashboard that displays real-time stock prices for a set of companies. The stock prices are available through an API.
Expected Answer:
- Use Power BI Desktop to connect to the API.
- Go to "Get Data" > "Web" and enter the API URL.
- Configure the data refresh settings to ensure real-time updates (e.g., setting up a scheduled refresh or using DirectQuery if supported).
- Create visualizations using the imported data.
- Publish the report to the Power BI service and set up a data gateway if needed for continuous refresh.
3. Scenario: You have been given a Power BI report that contains multiple visualizations. The report is taking a long time to load and is impacting the performance of the application.
Expected Answer:
- Analyze the current performance using Performance Analyzer.
- Optimize data model by reducing the number of columns and rows, and removing unnecessary calculations.
- Use aggregated tables to pre-compute results.
- Simplify DAX calculations.
- Optimize visualizations by reducing the number of visuals per page and avoiding complex custom visuals.
- Ensure proper indexing on the data source.
Free SQL Resources: t.iss.one/mysqldata
Like if you need more similar content
Hope it helps :)
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