Data Analytics isn't rocket science. It's just a different language.
Here's a beginner's guide to the world of data analytics:
1) Understand the fundamentals:
- Mathematics
- Statistics
- Technology
2) Learn the tools:
- SQL
- Python
- Excel (yes, it's still relevant!)
3) Understand the data:
- What do you want to measure?
- How are you measuring it?
- What metrics are important to you?
4) Data Visualization:
- A picture is worth a thousand words
5) Practice:
- There's no better way to learn than to do it yourself.
Data Analytics is a valuable skill that can help you make better decisions, understand your audience better, and ultimately grow your business.
It's never too late to start learning!
Here's a beginner's guide to the world of data analytics:
1) Understand the fundamentals:
- Mathematics
- Statistics
- Technology
2) Learn the tools:
- SQL
- Python
- Excel (yes, it's still relevant!)
3) Understand the data:
- What do you want to measure?
- How are you measuring it?
- What metrics are important to you?
4) Data Visualization:
- A picture is worth a thousand words
5) Practice:
- There's no better way to learn than to do it yourself.
Data Analytics is a valuable skill that can help you make better decisions, understand your audience better, and ultimately grow your business.
It's never too late to start learning!
โค12
๐How to create Formulas To Calculate Values
Entering the cell references for 15 or 20 cells in a calculation would be tedious, but in Excel you can easily enter complex calculations by using the Insert Function dialog box.
The Insert Function dialog box includes a list of functions, or predefined formulas, from which you can choose.
-Average = finds the average of the numbers in the specified cells
-Sum = finds the total/sum of the numbers in the specified cells
-Count = finds the number of entities in the specified cells
-Max = finds the largest value in the specified cells
-Min = finds the smallest values in the specified cells
Entering the cell references for 15 or 20 cells in a calculation would be tedious, but in Excel you can easily enter complex calculations by using the Insert Function dialog box.
The Insert Function dialog box includes a list of functions, or predefined formulas, from which you can choose.
-Average = finds the average of the numbers in the specified cells
-Sum = finds the total/sum of the numbers in the specified cells
-Count = finds the number of entities in the specified cells
-Max = finds the largest value in the specified cells
-Min = finds the smallest values in the specified cells
โค5๐ฅ4๐3๐1
Data Analytics isnโt SQL.
Data Analytics isnโt dashboards.
Data Analytics isnโt Python.
Data Analytics isnโt even โfinding insights.โ
Data Analytics is spending weeks on analysis, only for someone earning 5x more to say, โJust send it in Excel.โ
Data Analytics isnโt dashboards.
Data Analytics isnโt Python.
Data Analytics isnโt even โfinding insights.โ
Data Analytics is spending weeks on analysis, only for someone earning 5x more to say, โJust send it in Excel.โ
๐21โค15๐6๐1
Most Asked SQL Interview Questions at MAANG Companies๐ฅ๐ฅ
Preparing for an SQL Interview at MAANG Companies? Here are some crucial SQL Questions you should be ready to tackle:
1. How do you retrieve all columns from a table?
SELECT * FROM table_name;
2. What SQL statement is used to filter records?
SELECT * FROM table_name
WHERE condition;
The WHERE clause is used to filter records based on a specified condition.
3. How can you join multiple tables? Describe different types of JOINs.
SELECT columns
FROM table1
JOIN table2 ON table1.column = table2.column
JOIN table3 ON table2.column = table3.column;
Types of JOINs:
1. INNER JOIN: Returns records with matching values in both tables
SELECT * FROM table1
INNER JOIN table2 ON table1.column = table2.column;
2. LEFT JOIN: Returns all records from the left table & matched records from the right table. Unmatched records will have NULL values.
SELECT * FROM table1
LEFT JOIN table2 ON table1.column = table2.column;
3. RIGHT JOIN: Returns all records from the right table & matched records from the left table. Unmatched records will have NULL values.
SELECT * FROM table1
RIGHT JOIN table2 ON table1.column = table2.column;
4. FULL JOIN: Returns records when there is a match in either left or right table. Unmatched records will have NULL values.
SELECT * FROM table1
FULL JOIN table2 ON table1.column = table2.column;
4. What is the difference between WHERE & HAVING clauses?
WHERE: Filters records before any groupings are made.
SELECT * FROM table_name
WHERE condition;
HAVING: Filters records after groupings are made.
SELECT column, COUNT(*)
FROM table_name
GROUP BY column
HAVING COUNT(*) > value;
5. How do you calculate average, sum, minimum & maximum values in a column?
Average: SELECT AVG(column_name) FROM table_name;
Sum: SELECT SUM(column_name) FROM table_name;
Minimum: SELECT MIN(column_name) FROM table_name;
Maximum: SELECT MAX(column_name) FROM table_name;
Here you can find essential SQL Interview Resources๐
https://t.iss.one/mysqldata
Like this post if you need more ๐โค๏ธ
Hope it helps :)
Preparing for an SQL Interview at MAANG Companies? Here are some crucial SQL Questions you should be ready to tackle:
1. How do you retrieve all columns from a table?
SELECT * FROM table_name;
2. What SQL statement is used to filter records?
SELECT * FROM table_name
WHERE condition;
The WHERE clause is used to filter records based on a specified condition.
3. How can you join multiple tables? Describe different types of JOINs.
SELECT columns
FROM table1
JOIN table2 ON table1.column = table2.column
JOIN table3 ON table2.column = table3.column;
Types of JOINs:
1. INNER JOIN: Returns records with matching values in both tables
SELECT * FROM table1
INNER JOIN table2 ON table1.column = table2.column;
2. LEFT JOIN: Returns all records from the left table & matched records from the right table. Unmatched records will have NULL values.
SELECT * FROM table1
LEFT JOIN table2 ON table1.column = table2.column;
3. RIGHT JOIN: Returns all records from the right table & matched records from the left table. Unmatched records will have NULL values.
SELECT * FROM table1
RIGHT JOIN table2 ON table1.column = table2.column;
4. FULL JOIN: Returns records when there is a match in either left or right table. Unmatched records will have NULL values.
SELECT * FROM table1
FULL JOIN table2 ON table1.column = table2.column;
4. What is the difference between WHERE & HAVING clauses?
WHERE: Filters records before any groupings are made.
SELECT * FROM table_name
WHERE condition;
HAVING: Filters records after groupings are made.
SELECT column, COUNT(*)
FROM table_name
GROUP BY column
HAVING COUNT(*) > value;
5. How do you calculate average, sum, minimum & maximum values in a column?
Average: SELECT AVG(column_name) FROM table_name;
Sum: SELECT SUM(column_name) FROM table_name;
Minimum: SELECT MIN(column_name) FROM table_name;
Maximum: SELECT MAX(column_name) FROM table_name;
Here you can find essential SQL Interview Resources๐
https://t.iss.one/mysqldata
Like this post if you need more ๐โค๏ธ
Hope it helps :)
โค5
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.
Like for more free Cheatsheets โค๏ธ
Share with credits: https://t.iss.one/sqlspecialist
Hope it helps :)
#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
โค4
Top 5 data analysis interview questions with answers ๐๐
Question 1: How would you approach a new data analysis project?
Ideal answer:
I would approach a new data analysis project by following these steps:
Understand the business goals. What is the purpose of the data analysis? What questions are we trying to answer?
Gather the data. This may involve collecting data from different sources, such as databases, spreadsheets, and surveys.
Clean and prepare the data. This may involve removing duplicate data, correcting errors, and formatting the data in a consistent way.
Explore the data. This involves using data visualization and statistical analysis to understand the data and identify any patterns or trends.
Build a model or hypothesis. This involves using the data to develop a model or hypothesis that can be used to answer the business questions.
Test the model or hypothesis. This involves using the data to test the model or hypothesis and see how well it performs.
Interpret and communicate the results. This involves explaining the results of the data analysis to stakeholders in a clear and concise way.
Question 2: What are some of the challenges you have faced in previous data analysis projects, and how did you overcome them?
Ideal answer:
One of the biggest challenges I have faced in previous data analysis projects is dealing with missing data. I have overcome this challenge by using a variety of techniques, such as imputation and machine learning.
Another challenge I have faced is dealing with large datasets. I have overcome this challenge by using efficient data processing techniques and by using cloud computing platforms.
Question 3: Can you describe a time when you used data analysis to solve a business problem?
Ideal answer:
In my previous role at a retail company, I was tasked with identifying the products that were most likely to be purchased together. I used data analysis to identify patterns in the purchase data and to develop a model that could predict which products were most likely to be purchased together. This model was used to improve the company's product recommendations and to increase sales.
Question 4: What are some of your favorite data analysis tools and techniques?
Ideal answer:
Some of my favorite data analysis tools and techniques include:
Programming languages such as Python and R
Data visualization tools such as Tableau and Power BI
Statistical analysis tools such as SPSS and SAS
Machine learning algorithms such as linear regression and decision trees
Question 5: How do you stay up-to-date on the latest trends and developments in data analysis?
Ideal answer:
I stay up-to-date on the latest trends and developments in data analysis by reading industry publications, attending conferences, and taking online courses. I also follow thought leaders on social media and subscribe to newsletters.
By providing thoughtful and well-informed answers to these questions, you can demonstrate to your interviewer that you have the analytical skills and knowledge necessary to be successful in the role.
Like this post if you want more interview questions with detailed answers to be posted in the channel ๐โค๏ธ
Share with credits: https://t.iss.one/sqlspecialist
Hope it helps :)
Question 1: How would you approach a new data analysis project?
Ideal answer:
I would approach a new data analysis project by following these steps:
Understand the business goals. What is the purpose of the data analysis? What questions are we trying to answer?
Gather the data. This may involve collecting data from different sources, such as databases, spreadsheets, and surveys.
Clean and prepare the data. This may involve removing duplicate data, correcting errors, and formatting the data in a consistent way.
Explore the data. This involves using data visualization and statistical analysis to understand the data and identify any patterns or trends.
Build a model or hypothesis. This involves using the data to develop a model or hypothesis that can be used to answer the business questions.
Test the model or hypothesis. This involves using the data to test the model or hypothesis and see how well it performs.
Interpret and communicate the results. This involves explaining the results of the data analysis to stakeholders in a clear and concise way.
Question 2: What are some of the challenges you have faced in previous data analysis projects, and how did you overcome them?
Ideal answer:
One of the biggest challenges I have faced in previous data analysis projects is dealing with missing data. I have overcome this challenge by using a variety of techniques, such as imputation and machine learning.
Another challenge I have faced is dealing with large datasets. I have overcome this challenge by using efficient data processing techniques and by using cloud computing platforms.
Question 3: Can you describe a time when you used data analysis to solve a business problem?
Ideal answer:
In my previous role at a retail company, I was tasked with identifying the products that were most likely to be purchased together. I used data analysis to identify patterns in the purchase data and to develop a model that could predict which products were most likely to be purchased together. This model was used to improve the company's product recommendations and to increase sales.
Question 4: What are some of your favorite data analysis tools and techniques?
Ideal answer:
Some of my favorite data analysis tools and techniques include:
Programming languages such as Python and R
Data visualization tools such as Tableau and Power BI
Statistical analysis tools such as SPSS and SAS
Machine learning algorithms such as linear regression and decision trees
Question 5: How do you stay up-to-date on the latest trends and developments in data analysis?
Ideal answer:
I stay up-to-date on the latest trends and developments in data analysis by reading industry publications, attending conferences, and taking online courses. I also follow thought leaders on social media and subscribe to newsletters.
By providing thoughtful and well-informed answers to these questions, you can demonstrate to your interviewer that you have the analytical skills and knowledge necessary to be successful in the role.
Like this post if you want more interview questions with detailed answers to be posted in the channel ๐โค๏ธ
Share with credits: https://t.iss.one/sqlspecialist
Hope it helps :)
โค10๐2
Soft skills questions will be part of your next data job interview!
Here is what you should prepare for:
1. ๐๐ผ๐บ๐บ๐๐ป๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป: Be ready to discuss how you explain complex data insights to non-technical stakeholders.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you ensure that your data insights are understood and get used by non-technical stakeholders?โ
2. ๐ง๐ฒ๐ฎ๐บ ๐๐ผ๐น๐น๐ฎ๐ฏ๐ผ๐ฟ๐ฎ๐๐ถ๐ผ๐ป: Show your ability to work well with others.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โCan you talk about a time when you had to manage a conflict within a team? How did you resolve it?โ
3. ๐ฃ๐ฟ๐ผ๐ฏ๐น๐ฒ๐บ-๐ฆ๐ผ๐น๐๐ถ๐ป๐ด: Highlight your critical thinking and problem-solving skills.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โDescribe a situation where you had to make a quick decision based on incomplete data. What was the outcome?โ
4. ๐๐ฑ๐ฎ๐ฝ๐๐ฎ๐ฏ๐ถ๐น๐ถ๐๐: Demonstrate your flexibility and openness to change.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you handle sudden changes in project priorities or scope?โ
5. ๐ง๐ถ๐บ๐ฒ ๐ ๐ฎ๐ป๐ฎ๐ด๐ฒ๐บ๐ฒ๐ป๐: Prove your ability to manage multiple tasks and deadlines.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โTell me about a time when you were under tight deadlines. How did you manage to meet them?โ
6. ๐๐บ๐ฝ๐ฎ๐๐ต๐ ๐ฎ๐ป๐ฑ ๐จ๐ป๐ฑ๐ฒ๐ฟ๐๐๐ฎ๐ป๐ฑ๐ถ๐ป๐ด: Show your ability to understand stakeholder needs.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you approach understanding the needs of different stakeholders when starting a new project?โ
Structure your answers using the STAR method (Situation, Task, Action, Result). This helps you provide clear and concise responses that highlight your skills.
By preparing for these soft skills questions, youโll demonstrate that youโre not just technically fit, but also a well-rounded professional ready to make an impact on the business.
You can find useful tips to improve your soft skills here: ๐ https://t.iss.one/englishlearnerspro/
Here is what you should prepare for:
1. ๐๐ผ๐บ๐บ๐๐ป๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป: Be ready to discuss how you explain complex data insights to non-technical stakeholders.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you ensure that your data insights are understood and get used by non-technical stakeholders?โ
2. ๐ง๐ฒ๐ฎ๐บ ๐๐ผ๐น๐น๐ฎ๐ฏ๐ผ๐ฟ๐ฎ๐๐ถ๐ผ๐ป: Show your ability to work well with others.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โCan you talk about a time when you had to manage a conflict within a team? How did you resolve it?โ
3. ๐ฃ๐ฟ๐ผ๐ฏ๐น๐ฒ๐บ-๐ฆ๐ผ๐น๐๐ถ๐ป๐ด: Highlight your critical thinking and problem-solving skills.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โDescribe a situation where you had to make a quick decision based on incomplete data. What was the outcome?โ
4. ๐๐ฑ๐ฎ๐ฝ๐๐ฎ๐ฏ๐ถ๐น๐ถ๐๐: Demonstrate your flexibility and openness to change.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you handle sudden changes in project priorities or scope?โ
5. ๐ง๐ถ๐บ๐ฒ ๐ ๐ฎ๐ป๐ฎ๐ด๐ฒ๐บ๐ฒ๐ป๐: Prove your ability to manage multiple tasks and deadlines.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โTell me about a time when you were under tight deadlines. How did you manage to meet them?โ
6. ๐๐บ๐ฝ๐ฎ๐๐ต๐ ๐ฎ๐ป๐ฑ ๐จ๐ป๐ฑ๐ฒ๐ฟ๐๐๐ฎ๐ป๐ฑ๐ถ๐ป๐ด: Show your ability to understand stakeholder needs.
๐๐น๐ข๐ฎ๐ฑ๐ญ๐ฆ ๐ฒ๐ถ๐ฆ๐ด๐ต๐ช๐ฐ๐ฏ:
โHow do you approach understanding the needs of different stakeholders when starting a new project?โ
Structure your answers using the STAR method (Situation, Task, Action, Result). This helps you provide clear and concise responses that highlight your skills.
By preparing for these soft skills questions, youโll demonstrate that youโre not just technically fit, but also a well-rounded professional ready to make an impact on the business.
You can find useful tips to improve your soft skills here: ๐ https://t.iss.one/englishlearnerspro/
โค8
๐ฏ Top 20 SQL Interview Questions You Must Know
SQL is one of the most in-demand skills for Data Analysts.
Here are 20 SQL interview questions that frequently appear in job interviews.
๐ Basic SQL Questions
1๏ธโฃ What is the difference between INNER JOIN and LEFT JOIN?
2๏ธโฃ How does GROUP BY work, and why do we use it?
3๏ธโฃ What is the difference between HAVING and WHERE?
4๏ธโฃ How do you remove duplicate rows from a table?
5๏ธโฃ What is the difference between RANK(), DENSE_RANK(), and ROW_NUMBER()?
๐ Intermediate SQL Questions
6๏ธโฃ How do you find the second highest salary from an Employee table?
7๏ธโฃ What is a Common Table Expression (CTE), and when should you use it?
8๏ธโฃ How do you identify missing values in a dataset using SQL?
9๏ธโฃ What is the difference between UNION and UNION ALL?
๐ How do you calculate a running total in SQL?
๐ Advanced SQL Questions
1๏ธโฃ1๏ธโฃ How does a self-join work? Give an example.
1๏ธโฃ2๏ธโฃ What is a window function, and how is it different from GROUP BY?
1๏ธโฃ3๏ธโฃ How do you detect and remove duplicate records in SQL?
1๏ธโฃ4๏ธโฃ Explain the difference between EXISTS and IN.
1๏ธโฃ5๏ธโฃ What is the purpose of COALESCE()?
๐ Real-World SQL Scenarios
1๏ธโฃ6๏ธโฃ How do you optimize a slow SQL query?
1๏ธโฃ7๏ธโฃ What is indexing in SQL, and how does it improve performance?
1๏ธโฃ8๏ธโฃ Write an SQL query to find customers who have placed more than 3 orders.
1๏ธโฃ9๏ธโฃ How do you calculate the percentage of total sales for each category?
2๏ธโฃ0๏ธโฃ What is the use of CASE statements in SQL?
You can find detailed answers here! โฌ๏ธ
https://t.iss.one/sqlspecialist/1112
Hope it helps :)
SQL is one of the most in-demand skills for Data Analysts.
Here are 20 SQL interview questions that frequently appear in job interviews.
๐ Basic SQL Questions
1๏ธโฃ What is the difference between INNER JOIN and LEFT JOIN?
2๏ธโฃ How does GROUP BY work, and why do we use it?
3๏ธโฃ What is the difference between HAVING and WHERE?
4๏ธโฃ How do you remove duplicate rows from a table?
5๏ธโฃ What is the difference between RANK(), DENSE_RANK(), and ROW_NUMBER()?
๐ Intermediate SQL Questions
6๏ธโฃ How do you find the second highest salary from an Employee table?
7๏ธโฃ What is a Common Table Expression (CTE), and when should you use it?
8๏ธโฃ How do you identify missing values in a dataset using SQL?
9๏ธโฃ What is the difference between UNION and UNION ALL?
๐ How do you calculate a running total in SQL?
๐ Advanced SQL Questions
1๏ธโฃ1๏ธโฃ How does a self-join work? Give an example.
1๏ธโฃ2๏ธโฃ What is a window function, and how is it different from GROUP BY?
1๏ธโฃ3๏ธโฃ How do you detect and remove duplicate records in SQL?
1๏ธโฃ4๏ธโฃ Explain the difference between EXISTS and IN.
1๏ธโฃ5๏ธโฃ What is the purpose of COALESCE()?
๐ Real-World SQL Scenarios
1๏ธโฃ6๏ธโฃ How do you optimize a slow SQL query?
1๏ธโฃ7๏ธโฃ What is indexing in SQL, and how does it improve performance?
1๏ธโฃ8๏ธโฃ Write an SQL query to find customers who have placed more than 3 orders.
1๏ธโฃ9๏ธโฃ How do you calculate the percentage of total sales for each category?
2๏ธโฃ0๏ธโฃ What is the use of CASE statements in SQL?
You can find detailed answers here! โฌ๏ธ
https://t.iss.one/sqlspecialist/1112
Hope it helps :)
โค7
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.
โค9
Complete Roadmap to learn SQL in 2025 ๐๐
1. Basic Concepts
- Understand databases and SQL.
- Learn data types (INT, VARCHAR, DATE, etc.).
2. Basic Queries
- SELECT: Retrieve data.
- WHERE: Filter results.
- ORDER BY: Sort results.
- LIMIT: Restrict results.
3. Aggregate Functions
- COUNT, SUM, AVG, MAX, MIN.
- Use GROUP BY to group results.
4. Joins
- INNER JOIN: Combine rows from two tables based on a condition.
- LEFT JOIN: Include all rows from the left table.
- RIGHT JOIN: Include all rows from the right table.
- FULL OUTER JOIN: Include all rows from both tables.
5. Subqueries
- Use nested queries for complex data retrieval.
6. Data Manipulation
- INSERT: Add new records.
- UPDATE: Modify existing records.
- DELETE: Remove records.
7. Schema Management
- CREATE TABLE: Define new tables.
- ALTER TABLE: Modify existing tables.
- DROP TABLE: Remove tables.
8. Indexes
- Understand how to create and use indexes to optimize queries.
9. Views
- Create and manage views for simplified data access.
10. Transactions
- Learn about COMMIT and ROLLBACK for data integrity.
11. Advanced Topics
- Stored Procedures: Automate complex tasks.
- Triggers: Execute actions automatically based on events.
- Normalization: Understand database design principles.
12. Practice
- Use platforms like LeetCode, HackerRank, or learnsql for hands-on practice.
Here are some free resources to learn & practice SQL ๐๐
SQL For Data Analysis: https://t.iss.one/sqlanalyst
For Practice- https://stratascratch.com/?via=free
SQL Learning Series: https://t.iss.one/sqlspecialist/567
Top 10 SQL Projects with Datasets: https://t.iss.one/DataPortfolio/16
Join for more free resources: https://t.iss.one/free4unow_backup
ENJOY LEARNING ๐๐
1. Basic Concepts
- Understand databases and SQL.
- Learn data types (INT, VARCHAR, DATE, etc.).
2. Basic Queries
- SELECT: Retrieve data.
- WHERE: Filter results.
- ORDER BY: Sort results.
- LIMIT: Restrict results.
3. Aggregate Functions
- COUNT, SUM, AVG, MAX, MIN.
- Use GROUP BY to group results.
4. Joins
- INNER JOIN: Combine rows from two tables based on a condition.
- LEFT JOIN: Include all rows from the left table.
- RIGHT JOIN: Include all rows from the right table.
- FULL OUTER JOIN: Include all rows from both tables.
5. Subqueries
- Use nested queries for complex data retrieval.
6. Data Manipulation
- INSERT: Add new records.
- UPDATE: Modify existing records.
- DELETE: Remove records.
7. Schema Management
- CREATE TABLE: Define new tables.
- ALTER TABLE: Modify existing tables.
- DROP TABLE: Remove tables.
8. Indexes
- Understand how to create and use indexes to optimize queries.
9. Views
- Create and manage views for simplified data access.
10. Transactions
- Learn about COMMIT and ROLLBACK for data integrity.
11. Advanced Topics
- Stored Procedures: Automate complex tasks.
- Triggers: Execute actions automatically based on events.
- Normalization: Understand database design principles.
12. Practice
- Use platforms like LeetCode, HackerRank, or learnsql for hands-on practice.
Here are some free resources to learn & practice SQL ๐๐
SQL For Data Analysis: https://t.iss.one/sqlanalyst
For Practice- https://stratascratch.com/?via=free
SQL Learning Series: https://t.iss.one/sqlspecialist/567
Top 10 SQL Projects with Datasets: https://t.iss.one/DataPortfolio/16
Join for more free resources: https://t.iss.one/free4unow_backup
ENJOY LEARNING ๐๐
โค16๐1
Some practical interview questions for an entry-level data analyst role in Power BI:
โข Data Import Scenario: Describe how you would import data from various sources (Excel,SQL Server, CSV) into Power BI.
โข Data Cleaning Exercise: In Power BI, how would you handle a dataset with missing values and inconsistent formats to prepare it for analysis?
โข Handling Large Datasets: If you're working with a very large dataset in Power BI that is causing performance issues, what strategies would you use to optimize the data processing?
โข Calculated Columns and Measures: Explain how you would use calculated columns and measures in Power BI to analyze year-over-year growth.
โข Data Modeling Case: You have sales data in one table and customer data in another. How would you create a data model in Power BI to analyze customer purchase behavior?
โข Visualizations Task: Describe your approach to visualizing sales data in Power BI to highlight trends over time across different product categories.
โข Dashboard Optimization: A Power BI dashboard is loading slowly. What steps would you take to diagnose and improve its performance?
โข Data Refresh Scheduling: How would you set up and manage automatic data refreshes for a weekly sales report in Power BI?
โข Row-Level Security: How would you implement user-level security in Power BI for a report that needs different access levels for various users?
โข Troubleshooting a DAX Calculation: If a DAX formula in Power BI is not returning the expected results, how would you go about troubleshooting it?
โข Integration with Other Tools: Describe a scenario where you integrated Power BI with another tool or service (like Excel, Azure, or a web API).
โข Interactive Reports Creation: How would you design a Power BI report that allows user interaction, such as using slicers or drill-down features?
โข Adapting to Data Source Changes: If there are structural changes in a primary data source (like addition or removal of columns), how would you update your Power BI reports and dashboards?
โข Sharing Reports: Explain how you would share a report with your team and set up access controls using Power BI Service.
โข SQL Queries in Power BI: How do you use SQL queries in Power BI for advanced data transformation or analysis?
โข Error Handling in Data Sources: How do you manage and resolve errors in data sources or calculations in Power BI?
โข Custom Visuals Usage: Have you used custom visuals in Power BI? Describe the scenario and the benefit
โข Collaboration in Power BI Projects: Discuss how you have worked with others on a Power BI project. What collaboration tools or features within Power BI did you utilize?
โข Performance Tuning: What steps do you take to ensure your Power BI reports are performing optimally when dealing with large datasets or complex calculations?
Power BI Interviews ๐๐
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope you'll like it
Like this post if you need more resources like this ๐โค๏ธ
โข Data Import Scenario: Describe how you would import data from various sources (Excel,SQL Server, CSV) into Power BI.
โข Data Cleaning Exercise: In Power BI, how would you handle a dataset with missing values and inconsistent formats to prepare it for analysis?
โข Handling Large Datasets: If you're working with a very large dataset in Power BI that is causing performance issues, what strategies would you use to optimize the data processing?
โข Calculated Columns and Measures: Explain how you would use calculated columns and measures in Power BI to analyze year-over-year growth.
โข Data Modeling Case: You have sales data in one table and customer data in another. How would you create a data model in Power BI to analyze customer purchase behavior?
โข Visualizations Task: Describe your approach to visualizing sales data in Power BI to highlight trends over time across different product categories.
โข Dashboard Optimization: A Power BI dashboard is loading slowly. What steps would you take to diagnose and improve its performance?
โข Data Refresh Scheduling: How would you set up and manage automatic data refreshes for a weekly sales report in Power BI?
โข Row-Level Security: How would you implement user-level security in Power BI for a report that needs different access levels for various users?
โข Troubleshooting a DAX Calculation: If a DAX formula in Power BI is not returning the expected results, how would you go about troubleshooting it?
โข Integration with Other Tools: Describe a scenario where you integrated Power BI with another tool or service (like Excel, Azure, or a web API).
โข Interactive Reports Creation: How would you design a Power BI report that allows user interaction, such as using slicers or drill-down features?
โข Adapting to Data Source Changes: If there are structural changes in a primary data source (like addition or removal of columns), how would you update your Power BI reports and dashboards?
โข Sharing Reports: Explain how you would share a report with your team and set up access controls using Power BI Service.
โข SQL Queries in Power BI: How do you use SQL queries in Power BI for advanced data transformation or analysis?
โข Error Handling in Data Sources: How do you manage and resolve errors in data sources or calculations in Power BI?
โข Custom Visuals Usage: Have you used custom visuals in Power BI? Describe the scenario and the benefit
โข Collaboration in Power BI Projects: Discuss how you have worked with others on a Power BI project. What collaboration tools or features within Power BI did you utilize?
โข Performance Tuning: What steps do you take to ensure your Power BI reports are performing optimally when dealing with large datasets or complex calculations?
Power BI Interviews ๐๐
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Hope you'll like it
Like this post if you need more resources like this ๐โค๏ธ
โค3
Data Analytics Roadmap
1. Fundamentals of Statistics and Mathematics
- Understand descriptive statistics: mean, median, mode, variance, standard deviation.
- Basics of probability theory.
- Hypothesis testing and statistical inference.
- Some linear algebra and calculus basics (optional depending on needs).
2. Learn Excel and Google Sheets
- Master spreadsheet basics: formulas, functions, pivot tables.
- Data visualization with charts and graphs.
- Basic automation with macros and advanced formulas.
3. Programming for Data Analytics
- Choose Python or R as your main analytical programming language.
- Python libraries: pandas (data manipulation), numpy (numerical operations), matplotlib and seaborn (visualization).
- For R: dplyr, ggplot2.
- Use Jupyter Notebook (Python) or RStudio for coding environment.
4. Databases and SQL
- Understand relational databases and how data is stored.
- Learn SQL queries: SELECT, JOIN, GROUP BY, aggregation functions.
- Practice querying real databases.
5. Data Visualization Tools
- Learn tools like Tableau, Power BI, or Looker.
- Build interactive dashboards and reports.
- Understand best practices for effective visualization (color, simplicity, clarity).
6. Business Analytics Fundamentals
- Understand business processes and workflows.
- Define Key Performance Indicators (KPIs).
- Translate business questions into analytical problems.
7. Data Cleaning and Preprocessing
- Handle missing, inconsistent, and outlier data.
- Data transformation and normalization techniques.
- Use Python (pandas) or other tools to clean data effectively.
8. Basics of Machine Learning (Optional for Advanced Skills)
- Understand simple models: linear regression, classification.
- Use scikit-learn library in Python.
- Apply models for forecasting and clustering.
9. Hands-on Practice and Projects
- Work on real datasets from Kaggle or other platforms.
- Build a portfolio showcasing your data analysis projects.
- Participate in data competitions and hackathons.
10. Communication and Reporting
- Develop skills in presenting data insights clearly.
- Create compelling reports and presentations.
- Learn to work with stakeholders to tailor insights.
Share with credits: https://t.iss.one/sqlspecialist
React โฅ๏ธ for more
1. Fundamentals of Statistics and Mathematics
- Understand descriptive statistics: mean, median, mode, variance, standard deviation.
- Basics of probability theory.
- Hypothesis testing and statistical inference.
- Some linear algebra and calculus basics (optional depending on needs).
2. Learn Excel and Google Sheets
- Master spreadsheet basics: formulas, functions, pivot tables.
- Data visualization with charts and graphs.
- Basic automation with macros and advanced formulas.
3. Programming for Data Analytics
- Choose Python or R as your main analytical programming language.
- Python libraries: pandas (data manipulation), numpy (numerical operations), matplotlib and seaborn (visualization).
- For R: dplyr, ggplot2.
- Use Jupyter Notebook (Python) or RStudio for coding environment.
4. Databases and SQL
- Understand relational databases and how data is stored.
- Learn SQL queries: SELECT, JOIN, GROUP BY, aggregation functions.
- Practice querying real databases.
5. Data Visualization Tools
- Learn tools like Tableau, Power BI, or Looker.
- Build interactive dashboards and reports.
- Understand best practices for effective visualization (color, simplicity, clarity).
6. Business Analytics Fundamentals
- Understand business processes and workflows.
- Define Key Performance Indicators (KPIs).
- Translate business questions into analytical problems.
7. Data Cleaning and Preprocessing
- Handle missing, inconsistent, and outlier data.
- Data transformation and normalization techniques.
- Use Python (pandas) or other tools to clean data effectively.
8. Basics of Machine Learning (Optional for Advanced Skills)
- Understand simple models: linear regression, classification.
- Use scikit-learn library in Python.
- Apply models for forecasting and clustering.
9. Hands-on Practice and Projects
- Work on real datasets from Kaggle or other platforms.
- Build a portfolio showcasing your data analysis projects.
- Participate in data competitions and hackathons.
10. Communication and Reporting
- Develop skills in presenting data insights clearly.
- Create compelling reports and presentations.
- Learn to work with stakeholders to tailor insights.
Share with credits: https://t.iss.one/sqlspecialist
React โฅ๏ธ for more
โค9๐1
What do you want to learn?
Anonymous Poll
32%
SQL
18%
Power BI
4%
Tableau
13%
Python
6%
Excel
14%
Machine Learning/ Data Science
9%
Artificial intelligence
4%
Statistics
๐12
SQL Basics for Beginners: Must-Know Concepts
1. What is SQL?
SQL (Structured Query Language) is a standard language used to communicate with databases. It allows you to query, update, and manage relational databases by writing simple or complex queries.
2. SQL Syntax
SQL is written using statements, which consist of keywords like
- SQL keywords are not case-sensitive, but it's common to write them in uppercase (e.g.,
3. SQL Data Types
Databases store data in different formats. The most common data types are:
-
-
-
-
4. Basic SQL Queries
Here are some fundamental SQL operations:
- SELECT Statement: Used to retrieve data from a database.
- WHERE Clause: Filters data based on conditions.
- ORDER BY: Sorts data in ascending (
- LIMIT: Limits the number of rows returned.
5. Filtering Data with WHERE Clause
The
You can use comparison operators like:
-
-
-
-
6. Aggregating Data
SQL provides functions to summarize or aggregate data:
- COUNT(): Counts the number of rows.
- SUM(): Adds up values in a column.
- AVG(): Calculates the average value.
- GROUP BY: Groups rows that have the same values into summary rows.
7. Joins in SQL
Joins combine data from two or more tables:
- INNER JOIN: Retrieves records with matching values in both tables.
- LEFT JOIN: Retrieves all records from the left table and matched records from the right table.
8. Inserting Data
To add new data to a table, you use the
9. Updating Data
You can update existing data in a table using the
10. Deleting Data
To remove data from a table, use the
Here you can find essential SQL Interview Resources๐
https://t.iss.one/DataSimplifier
Like this post if you need more ๐โค๏ธ
Hope it helps :)
1. What is SQL?
SQL (Structured Query Language) is a standard language used to communicate with databases. It allows you to query, update, and manage relational databases by writing simple or complex queries.
2. SQL Syntax
SQL is written using statements, which consist of keywords like
SELECT, FROM, WHERE, etc., to perform operations on the data.- SQL keywords are not case-sensitive, but it's common to write them in uppercase (e.g.,
SELECT, FROM).3. SQL Data Types
Databases store data in different formats. The most common data types are:
-
INT (Integer): For whole numbers.-
VARCHAR(n) or TEXT: For storing text data.-
DATE: For dates.-
DECIMAL: For precise decimal values, often used in financial calculations.4. Basic SQL Queries
Here are some fundamental SQL operations:
- SELECT Statement: Used to retrieve data from a database.
SELECT column1, column2 FROM table_name;
- WHERE Clause: Filters data based on conditions.
SELECT * FROM table_name WHERE condition;
- ORDER BY: Sorts data in ascending (
ASC) or descending (DESC) order.SELECT column1, column2 FROM table_name ORDER BY column1 ASC;
- LIMIT: Limits the number of rows returned.
SELECT * FROM table_name LIMIT 5;
5. Filtering Data with WHERE Clause
The
WHERE clause helps you filter data based on a condition:SELECT * FROM employees WHERE salary > 50000;
You can use comparison operators like:
-
=: Equal to-
>: Greater than-
<: Less than-
LIKE: For pattern matching6. Aggregating Data
SQL provides functions to summarize or aggregate data:
- COUNT(): Counts the number of rows.
SELECT COUNT(*) FROM table_name;
- SUM(): Adds up values in a column.
SELECT SUM(salary) FROM employees;
- AVG(): Calculates the average value.
SELECT AVG(salary) FROM employees;
- GROUP BY: Groups rows that have the same values into summary rows.
SELECT department, AVG(salary) FROM employees GROUP BY department;
7. Joins in SQL
Joins combine data from two or more tables:
- INNER JOIN: Retrieves records with matching values in both tables.
SELECT employees.name, departments.department
FROM employees
INNER JOIN departments
ON employees.department_id = departments.id;
- LEFT JOIN: Retrieves all records from the left table and matched records from the right table.
SELECT employees.name, departments.department
FROM employees
LEFT JOIN departments
ON employees.department_id = departments.id;
8. Inserting Data
To add new data to a table, you use the
INSERT INTO statement: INSERT INTO employees (name, position, salary) VALUES ('John Doe', 'Analyst', 60000);
9. Updating Data
You can update existing data in a table using the
UPDATE statement:UPDATE employees SET salary = 65000 WHERE name = 'John Doe';
10. Deleting Data
To remove data from a table, use the
DELETE statement:DELETE FROM employees WHERE name = 'John Doe';
Here you can find essential SQL Interview Resources๐
https://t.iss.one/DataSimplifier
Like this post if you need more ๐โค๏ธ
Hope it helps :)
โค13๐ฅ2