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, …): 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, …): Returns the first non-null value.


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#dataanalytics

Python for Data Analysis: Must-Know Libraries 👇👇

Python is one of the most powerful tools for Data Analysts, and these libraries will supercharge your data analysis workflow by helping you clean, manipulate, and visualize data efficiently.

🔥 Essential Python Libraries for Data Analysis:

✅ Pandas – The go-to library for data manipulation. It helps in filtering, grouping, merging datasets, handling missing values, and transforming data into a structured format.

📌 Example: Loading a CSV file and displaying the first 5 rows:

import pandas as pd df = pd.read_csv('data.csv') print(df.head()) 

✅ NumPy – Used for handling numerical data and performing complex calculations. It provides support for multi-dimensional arrays and efficient mathematical operations.

📌 Example: Creating an array and performing basic operations:

import numpy as np arr = np.array([10, 20, 30]) print(arr.mean()) # Calculates the average 

✅ Matplotlib & Seaborn – These are used for creating visualizations like line graphs, bar charts, and scatter plots to understand trends and patterns in data.

📌 Example: Creating a basic bar chart:

import matplotlib.pyplot as plt plt.bar(['A', 'B', 'C'], [5, 7, 3]) plt.show() 

✅ Scikit-Learn – A must-learn library if you want to apply machine learning techniques like regression, classification, and clustering on your dataset.

✅ OpenPyXL – Helps in automating Excel reports using Python by reading, writing, and modifying Excel files.

💡 Challenge for You!
Try writing a Python script that:
1️⃣ Reads a CSV file
2️⃣ Cleans missing data
3️⃣ Creates a simple visualization

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If you want to get a job as a machine learning engineer, don’t start by diving into the hottest libraries like PyTorch,TensorFlow, Langchain, etc.

Yes, you might hear a lot about them or some other trending technology of the year...but guess what!

Technologies evolve rapidly, especially in the age of AI, but core concepts are always seen as more valuable than expertise in any particular tool. Stop trying to perform a brain surgery without knowing anything about human anatomy.

Instead, here are basic skills that will get you further than mastering any framework:


𝐌𝐚𝐭𝐡𝐞𝐦𝐚𝐭𝐢𝐜𝐬 𝐚𝐧𝐝 𝐒𝐭𝐚𝐭𝐢𝐬𝐭𝐢𝐜𝐬 - My first exposure to probability and statistics was in college, and it felt abstract at the time, but these concepts are the backbone of ML.

You can start here: Khan Academy Statistics and Probability - https://www.khanacademy.org/math/statistics-probability

𝐋𝐢𝐧𝐞𝐚𝐫 𝐀𝐥𝐠𝐞𝐛𝐫𝐚 𝐚𝐧𝐝 𝐂𝐚𝐥𝐜𝐮𝐥𝐮𝐬 - Concepts like matrices, vectors, eigenvalues, and derivatives are fundamental to understanding how ml algorithms work. These are used in everything from simple regression to deep learning.

𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 - Should you learn Python, Rust, R, Julia, JavaScript, etc.? The best advice is to pick the language that is most frequently used for the type of work you want to do. I started with Python due to its simplicity and extensive library support, and it remains my go-to language for machine learning tasks.

You can start here: Automate the Boring Stuff with Python - https://automatetheboringstuff.com/

𝐀𝐥𝐠𝐨𝐫𝐢𝐭𝐡𝐦 𝐔𝐧𝐝𝐞𝐫𝐬𝐭𝐚𝐧𝐝𝐢𝐧𝐠 - Understand the fundamental algorithms before jumping to deep learning. This includes linear regression, decision trees, SVMs, and clustering algorithms.

𝐃𝐞𝐩𝐥𝐨𝐲𝐦𝐞𝐧𝐭 𝐚𝐧𝐝 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧:
Knowing how to take a model from development to production is invaluable. This includes understanding APIs, model optimization, and monitoring. Tools like Docker and Flask are often used in this process.

𝐂𝐥𝐨𝐮𝐝 𝐂𝐨𝐦𝐩𝐮𝐭𝐢𝐧𝐠 𝐚𝐧𝐝 𝐁𝐢𝐠 𝐃𝐚𝐭𝐚:
Familiarity with cloud platforms (AWS, Google Cloud, Azure) and big data tools (Spark) is increasingly important as datasets grow larger. These skills help you manage and process large-scale data efficiently.

You can start here: Google Cloud Machine Learning - https://cloud.google.com/learn/training/machinelearning-ai

I love frameworks and libraries, and they can make anyone's job easier.

But the more solid your foundation, the easier it will be to pick up any new technologies and actually validate whether they solve your problems.

Best Data Science & Machine Learning Resources: https://topmate.io/coding/914624

All the best 👍👍

80% of people who start learning data analytics never land a job.

Not because they lack skill

but because they get stuck in "preparation mode."

I was almost one of them.

I spent months:
-Taking courses.
-Watching YouTube tutorials.
-Practicing SQL and Power BI.

But when it came time to publish a project or apply for jobs
I hesitated.

“I need to learn more first.”
“My portfolio isn’t ready.”
“Maybe next month.”

Sound familiar?

You don’t need more knowledge
you need more execution.

Data analysts who build & share projects are 3X more likely to get hired.

The best analysts aren’t the smartest.
They’re the ones who take action.

-They publish dashboards, even if they aren’t perfect.
-They post case studies, even when they feel like imposters.
-They apply for jobs before they "feel ready"

Stop overthinking.

Pick a dataset, build something, and share it today.

One messy project is worth more than 100 courses you never use.

Advanced Skills to Elevate Your Data Analytics Career

1️⃣ SQL Optimization & Performance Tuning

🚀 Learn indexing, query optimization, and execution plans to handle large datasets efficiently.

2️⃣ Machine Learning Basics

🤖 Understand supervised and unsupervised learning, feature engineering, and model evaluation to enhance analytical capabilities.

3️⃣ Big Data Technologies

🏗️ Explore Spark, Hadoop, and cloud platforms like AWS, Azure, or Google Cloud for large-scale data processing.

4️⃣ Data Engineering Skills

⚙️ Learn ETL pipelines, data warehousing, and workflow automation to streamline data processing.

5️⃣ Advanced Python for Analytics

🐍 Master libraries like Scikit-Learn, TensorFlow, and Statsmodels for predictive analytics and automation.

6️⃣ A/B Testing & Experimentation

🎯 Design and analyze controlled experiments to drive data-driven decision-making.

7️⃣ Dashboard Design & UX

🎨 Build interactive dashboards with Power BI, Tableau, or Looker that enhance user experience.

8️⃣ Cloud Data Analytics

☁️ Work with cloud databases like BigQuery, Snowflake, and Redshift for scalable analytics.

9️⃣ Domain Expertise

💼 Gain industry-specific knowledge (e.g., finance, healthcare, e-commerce) to provide more relevant insights.

🔟 Soft Skills & Leadership

💡 Develop stakeholder management, storytelling, and mentorship skills to advance in your career.

Hope it helps :)

#dataanalytics

Excel Formulas Every Analyst Should Know

SUM(): Adds a range of numbers.

AVERAGE(): Calculates the average of a range.

VLOOKUP(): Searches for a value in the first column and returns a corresponding value.

HLOOKUP(): Searches for a value in the first row and returns a corresponding value.

INDEX(): Returns the value of a cell in a given range based on row and column numbers.

MATCH(): Finds the position of a value in a range.

IF(): Performs a logical test and returns one value for TRUE, another for FALSE.

COUNTIF(): Counts cells that meet a specific condition.

CONCATENATE(): Joins two or more text strings together.

LEFT()/RIGHT(): Extracts a specified number of characters from the left or right of a text string.

Excel Resources: t.iss.one/excel_data

I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02

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SQL Interview Questions !!

🎗 Write a query to find all employees whose salaries exceed the company's average salary.
🎗 Write a query to retrieve the names of employees who work in the same department as 'John Doe'.
🎗 Write a query to display the second highest salary from the Employee table without using the MAX function twice.
🎗 Write a query to find all customers who have placed more than five orders.
🎗 Write a query to count the total number of orders placed by each customer.
🎗 Write a query to list employees who joined the company within the last 6 months.
🎗 Write a query to calculate the total sales amount for each product.
🎗 Write a query to list all products that have never been sold.
🎗 Write a query to remove duplicate rows from a table.
🎗 Write a query to identify the top 10 customers who have not placed any orders in the past year.

Here you can find essential SQL Interview Resources👇
https://t.iss.one/mysqldata

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📊 Data Analyst Roadmap (2025)

Master the Skills That Top Companies Are Hiring For!

📍 1. Learn Excel / Google Sheets
Basic formulas & formatting
VLOOKUP, Pivot Tables, Charts
Data cleaning & conditional formatting

📍 2. Master SQL
SELECT, WHERE, ORDER BY
JOINs (INNER, LEFT, RIGHT)
GROUP BY, HAVING, LIMIT
Subqueries, CTEs, Window Functions

📍 3. Learn Data Visualization Tools
Power BI / Tableau (choose one)
Charts, filters, slicers
Dashboards & storytelling

📍 4. Get Comfortable with Statistics
Mean, Median, Mode, Std Dev
Probability basics
A/B Testing, Hypothesis Testing
Correlation & Regression

📍 5. Learn Python for Data Analysis (Optional but Powerful)
Pandas & NumPy for data handling
Seaborn, Matplotlib for visuals
Jupyter Notebooks for analysis

📍 6. Data Cleaning & Wrangling
Handle missing values
Fix data types, remove duplicates
Text processing & date formatting

📍 7. Understand Business Metrics
KPIs: Revenue, Churn, CAC, LTV
Think like a business analyst
Deliver actionable insights

📍 8. Communication & Storytelling
Present insights with clarity
Simplify complex data
Speak the language of stakeholders

📍 9. Version Control (Git & GitHub)
Track your projects
Build a data portfolio
Collaborate with the community

📍 10. Interview & Resume Preparation
Excel, SQL, case-based questions
Mock interviews + real projects
Resume with measurable achievements

✨ React ❤️ for more

Step-by-Step Approach to Learn Data Analytics

➊ Learn Programming Language → SQL & Python
↓
➋ Master Excel & Spreadsheets → Pivot Tables, VLOOKUP, Data Cleaning
↓
➌ SQL for Data Analysis → SELECT, JOINS, GROUP BY, Window Functions
↓
➍ Data Manipulation & Processing → Pandas, NumPy
↓
➎ Data Visualization → Power BI, Tableau, Matplotlib, Seaborn
↓
➏ Exploratory Data Analysis (EDA) → Missing Values, Outliers, Feature Engineering
↓
➐ Business Intelligence & Reporting → Dashboards, Storytelling with Data
↓
➑ Advanced Concepts → A/B Testing, Statistical Analysis, Machine Learning Basics

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📊 Data Analyst Roadmap (2025)

Master the Skills That Top Companies Are Hiring For!

📍 1. Learn Excel / Google Sheets
Basic formulas & formatting
VLOOKUP, Pivot Tables, Charts
Data cleaning & conditional formatting

📍 2. Master SQL
SELECT, WHERE, ORDER BY
JOINs (INNER, LEFT, RIGHT)
GROUP BY, HAVING, LIMIT
Subqueries, CTEs, Window Functions

📍 3. Learn Data Visualization Tools
Power BI / Tableau (choose one)
Charts, filters, slicers
Dashboards & storytelling

📍 4. Get Comfortable with Statistics
Mean, Median, Mode, Std Dev
Probability basics
A/B Testing, Hypothesis Testing
Correlation & Regression

📍 5. Learn Python for Data Analysis (Optional but Powerful)
Pandas & NumPy for data handling
Seaborn, Matplotlib for visuals
Jupyter Notebooks for analysis

📍 6. Data Cleaning & Wrangling
Handle missing values
Fix data types, remove duplicates
Text processing & date formatting

📍 7. Understand Business Metrics
KPIs: Revenue, Churn, CAC, LTV
Think like a business analyst
Deliver actionable insights

📍 8. Communication & Storytelling
Present insights with clarity
Simplify complex data
Speak the language of stakeholders

📍 9. Version Control (Git & GitHub)
Track your projects
Build a data portfolio
Collaborate with the community

📍 10. Interview & Resume Preparation
Excel, SQL, case-based questions
Mock interviews + real projects
Resume with measurable achievements

✨ React ❤️ for more

SQL Advanced Concepts for Data Analyst Interviews

1. Window Functions: Gain proficiency in window functions like ROW_NUMBER(), RANK(), DENSE_RANK(), NTILE(), and LAG()/LEAD(). These functions allow you to perform calculations across a set of table rows related to the current row without collapsing the result set into a single output.

2. Common Table Expressions (CTEs): Understand how to use CTEs with the WITH clause to create temporary result sets that can be referenced within a SELECT, INSERT, UPDATE, or DELETE statement. CTEs improve the readability and maintainability of complex queries.

3. Recursive CTEs: Learn how to use recursive CTEs to solve hierarchical or recursive data problems, such as navigating organizational charts or bill-of-materials structures.

4. Advanced Joins: Master complex join techniques, including self-joins (joining a table with itself), cross joins (Cartesian product), and using multiple joins in a single query.

5. Subqueries and Correlated Subqueries: Be adept at writing subqueries that return a single value or a set of values. Correlated subqueries, which reference columns from the outer query, are particularly powerful for row-by-row operations.

6. Indexing Strategies: Learn advanced indexing strategies, such as covering indexes, composite indexes, and partial indexes. Understand how to optimize query performance by designing the right indexes and when to use CLUSTERED versus NON-CLUSTERED indexes.

7. Query Optimization and Execution Plans: Develop skills in reading and interpreting SQL execution plans to understand how queries are executed. Use tools like EXPLAIN or EXPLAIN ANALYZE to identify performance bottlenecks and optimize query performance.

8. Stored Procedures: Understand how to create and use stored procedures to encapsulate complex SQL logic into reusable, modular code. Learn how to pass parameters, handle errors, and return multiple result sets from a stored procedure.

9. Triggers: Learn how to create triggers to automatically execute a specified action in response to certain events on a table (e.g., AFTER INSERT, BEFORE UPDATE). Triggers are useful for maintaining data integrity and automating workflows.

10. Transactions and Isolation Levels: Master the use of transactions to ensure that a series of SQL operations are executed as a single unit of work. Understand different isolation levels (READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, SERIALIZABLE) and their impact on data consistency and concurrency.

11. PIVOT and UNPIVOT: Use the PIVOT operator to transform row data into columnar data and UNPIVOT to convert columns back into rows. These operations are crucial for reshaping data for reporting and analysis.

12. Dynamic SQL: Learn how to write dynamic SQL queries that are constructed and executed at runtime. This is useful when the exact SQL query cannot be determined until runtime, such as in scenarios involving user-defined filters or conditional logic.

13. Data Partitioning: Understand how to implement data partitioning strategies, such as range partitioning or list partitioning, to manage large tables efficiently. Partitioning can significantly improve query performance and manageability.

14. Temporary Tables: Learn how to create and use temporary tables to store intermediate results within a session. Understand the differences between local and global temporary tables, and when to use them.

15. Materialized Views: Use materialized views to store the result of a query physically and update it periodically. This can drastically improve performance for complex queries that need to be executed frequently.

16. Handling Complex Data Types: Understand how to work with complex data types such as JSON, XML, and arrays. Learn how to store, query, and manipulate these types in SQL databases, including using functions like JSON_EXTRACT(), XMLQUERY(), or array functions.

Here you can find SQL Interview Resources👇
https://t.iss.one/DataSimplifier

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🎯 𝐄𝐬𝐬𝐞𝐧𝐭𝐢𝐚𝐥 𝐃𝐀𝐓𝐀 𝐀𝐍𝐀𝐋𝐘𝐒𝐓 𝐒𝐊𝐈𝐋𝐋𝐒 𝐓𝐡𝐚𝐭 𝐑𝐞𝐜𝐫𝐮𝐢𝐭𝐞𝐫𝐬 𝐋𝐨𝐨𝐤 𝐅𝐨𝐫 🎯

If you're applying for Data Analyst roles, having technical skills like SQL and Power BI is important—but recruiters look for more than just tools!

🔹 1️⃣ 𝐒𝐐𝐋 𝐢𝐬 𝐊𝐈𝐍𝐆 👑—𝐌𝐚𝐬𝐭𝐞𝐫 𝐈𝐭
✅ Know how to write optimized queries (not just SELECT * from everywhere!)
✅ Be comfortable with JOINS, CTEs, Window Functions & Performance Optimization
✅ Practice solving real-world business scenarios using SQL
💡 Example Question: How would you find the top 5 best-selling products in each category using SQL?

🔹 2️⃣ 𝐁𝐮𝐬𝐢𝐧𝐞𝐬𝐬 𝐀𝐜𝐮𝐦𝐞𝐧: 𝐓𝐡𝐢𝐧𝐤 𝐋𝐢𝐤𝐞 𝐚 𝐃𝐞𝐜𝐢𝐬𝐢𝐨𝐧-𝐌𝐚𝐤𝐞𝐫
✅ Understand the why behind the data—not just the numbers
✅ Learn how to frame insights for different stakeholders (Tech & Non-Tech)
✅ Use data storytelling—simplify complex findings into actionable takeaways
💡 Example: Instead of saying, "Revenue increased by 12%," say "Revenue increased 12% after launching a targeted discount campaign, driving a 20% increase in repeat purchases."

🔹 3️⃣ 𝐏𝐨𝐰𝐞𝐫 𝐁𝐈 / 𝐓𝐚𝐛𝐥𝐞𝐚𝐮—𝐌𝐚𝐤𝐞 𝐃𝐚𝐬𝐡𝐛𝐨𝐚𝐫𝐝𝐬 𝐓𝐡𝐚𝐭 𝐒𝐩𝐞𝐚𝐤!
✅ Avoid overloading dashboards with too many visuals—focus on key KPIs
✅ Use interactive elements (filters, drill-throughs) for better usability
✅ Keep visuals simple & clear—bar charts are better than complex pie charts!
💡 Tip: Before creating a dashboard, ask: "What business problem does this solve?"

🔹 4️⃣ 𝐏𝐲𝐭𝐡𝐨𝐧 & 𝐄𝐱𝐜𝐞𝐥—𝐇𝐚𝐧𝐝𝐥𝐞 𝐃𝐚𝐭𝐚 𝐄𝐟𝐟𝐢𝐜𝐢𝐞𝐧𝐭𝐥𝐲
✅ Python for data wrangling, EDA & automation (Pandas, NumPy, Seaborn)
✅ Excel for quick analysis, PivotTables, VLOOKUP/XLOOKUP, Power Query
✅ Know when to use Excel vs. Python (hint: small vs. large datasets)

Being a Data Analyst is more than just running queries—it’s about understanding the business, making insights actionable, and communicating effectively!

Free Resources: https://t.iss.one/sqlspecialist

Tableau Cheat Sheet ✅

This Tableau cheatsheet is designed to be your quick reference guide for data visualization and analysis using Tableau. Whether you’re a beginner learning the basics or an experienced user looking for a handy resource, this cheatsheet covers essential topics.

1. Connecting to Data
- Use *Connect* pane to connect to various data sources (Excel, SQL Server, Text files, etc.).

2. Data Preparation
- Data Interpreter: Clean data automatically using the Data Interpreter.
- Join Data: Combine data from multiple tables using joins (Inner, Left, Right, Outer).
- Union Data: Stack data from multiple tables with the same structure.

3. Creating Views
- Drag & Drop: Drag fields from the Data pane onto Rows, Columns, or Marks to create visualizations.
- Show Me: Use the *Show Me* panel to select different visualization types.

4. Types of Visualizations
- Bar Chart: Compare values across categories.
- Line Chart: Display trends over time.
- Pie Chart: Show proportions of a whole (use sparingly).
- Map: Visualize geographic data.
- Scatter Plot: Show relationships between two variables.

5. Filters
- Dimension Filters: Filter data based on categorical values.
- Measure Filters: Filter data based on numerical values.
- Context Filters: Set a context for other filters to improve performance.

6. Calculated Fields
- Create calculated fields to derive new data:
- Example: Sales Growth = SUM([Sales]) - SUM([Previous Sales])

7. Parameters
- Use parameters to allow user input and control measures dynamically.

8. Formatting
- Format fonts, colors, borders, and lines using the Format pane for better visual appeal.

9. Dashboards
- Combine multiple sheets into a dashboard using the *Dashboard* tab.
- Use dashboard actions (filter, highlight, URL) to create interactivity.

10. Story Points
- Create a story to guide users through insights with narrative and visualizations.

11. Publishing & Sharing
- Publish dashboards to Tableau Server or Tableau Online for sharing and collaboration.

12. Export Options
- Export to PDF or image for offline use.

13. Keyboard Shortcuts
- Show/Hide Sidebar: Ctrl+Alt+T
- Duplicate Sheet: Ctrl + D
- Undo: Ctrl + Z
- Redo: Ctrl + Y

14. Performance Optimization
- Use extracts instead of live connections for faster performance.
- Optimize calculations and filters to improve dashboard loading times.

Best Resources to learn Tableau: https://t.iss.one/PowerBI_analyst

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