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.
โค4
1. What data sources can Power BI connect to?
Ans: The list of data sources for Power BI is extensive, but it can be grouped into the following:
Files: Data can be imported from Excel (.xlsx, xlxm), Power BI Desktop files (.pbix) and Comma Separated Value (.csv).
Content Packs: It is a collection of related documents or files that are stored as a group. In Power BI, there are two types of content packs, firstly those from services providers like Google Analytics, Marketo, or Salesforce, and secondly those created and shared by other users in your organization.
Connectors to databases and other datasets such as Azure SQL, Database and SQL, Server Analysis Services tabular data, etc.
2. What are the different integrity rules present in the DBMS?
The different integrity rules present in DBMS are as follows:
Entity Integrity: This rule states that the value of the primary key can never be NULL. So, all the tuples in the column identified as the primary key should have a value.
Referential Integrity: This rule states that either the value of the foreign key is NULL or it should be the primary key of any other relation.
3. What are some common clauses used with SELECT query in SQL?
Some common SQL clauses used in conjuction with a SELECT query are as follows:
WHERE clause in SQL is used to filter records that are necessary, based on specific conditions.
ORDER BY clause in SQL is used to sort the records based on some field(s) in ascending (ASC) or descending order (DESC).
GROUP BY clause in SQL is used to group records with identical data and can be used in conjunction with some aggregation functions to produce summarized results from the database.
HAVING clause in SQL is used to filter records in combination with the GROUP BY clause. It is different from WHERE, since the WHERE clause cannot filter aggregated records.
4. What is the difference between count, counta, and countblank in Excel?
The count function is very often used in Excel. Here, letโs look at the difference between count, and itโs variants - counta and countblank.
1. COUNT
It counts the number of cells that contain numeric values only. Cells that have string values, special characters, and blank cells will not be counted.
2. COUNTA
It counts the number of cells that contain any form of content. Cells that have string values, special characters, and numeric values will be counted. However, a blank cell will not be counted.
3. COUNTBLANK
As the name suggests, it counts the number of blank cells only. Cells that have content will not be taken into consideration.
Ans: The list of data sources for Power BI is extensive, but it can be grouped into the following:
Files: Data can be imported from Excel (.xlsx, xlxm), Power BI Desktop files (.pbix) and Comma Separated Value (.csv).
Content Packs: It is a collection of related documents or files that are stored as a group. In Power BI, there are two types of content packs, firstly those from services providers like Google Analytics, Marketo, or Salesforce, and secondly those created and shared by other users in your organization.
Connectors to databases and other datasets such as Azure SQL, Database and SQL, Server Analysis Services tabular data, etc.
2. What are the different integrity rules present in the DBMS?
The different integrity rules present in DBMS are as follows:
Entity Integrity: This rule states that the value of the primary key can never be NULL. So, all the tuples in the column identified as the primary key should have a value.
Referential Integrity: This rule states that either the value of the foreign key is NULL or it should be the primary key of any other relation.
3. What are some common clauses used with SELECT query in SQL?
Some common SQL clauses used in conjuction with a SELECT query are as follows:
WHERE clause in SQL is used to filter records that are necessary, based on specific conditions.
ORDER BY clause in SQL is used to sort the records based on some field(s) in ascending (ASC) or descending order (DESC).
GROUP BY clause in SQL is used to group records with identical data and can be used in conjunction with some aggregation functions to produce summarized results from the database.
HAVING clause in SQL is used to filter records in combination with the GROUP BY clause. It is different from WHERE, since the WHERE clause cannot filter aggregated records.
4. What is the difference between count, counta, and countblank in Excel?
The count function is very often used in Excel. Here, letโs look at the difference between count, and itโs variants - counta and countblank.
1. COUNT
It counts the number of cells that contain numeric values only. Cells that have string values, special characters, and blank cells will not be counted.
2. COUNTA
It counts the number of cells that contain any form of content. Cells that have string values, special characters, and numeric values will be counted. However, a blank cell will not be counted.
3. COUNTBLANK
As the name suggests, it counts the number of blank cells only. Cells that have content will not be taken into consideration.
โค6๐1
๐ฆ๐ค๐ ๐ ๐๐๐-๐๐ป๐ผ๐ ๐๐ถ๐ณ๐ณ๐ฒ๐ฟ๐ฒ๐ป๐ฐ๐ฒ๐ ๐
Whether you're writing daily queries or preparing for interviews, understanding these subtle SQL differences can make a big impact on both performance and accuracy.
๐ง Hereโs a powerful visual that compares the most commonly misunderstood SQL concepts โ side by side.
๐ ๐๐ผ๐๐ฒ๐ฟ๐ฒ๐ฑ ๐ถ๐ป ๐๐ต๐ถ๐ ๐๐ป๐ฎ๐ฝ๐๐ต๐ผ๐:
๐น RANK() vs DENSE_RANK()
๐น HAVING vs WHERE
๐น UNION vs UNION ALL
๐น JOIN vs UNION
๐น CTE vs TEMP TABLE
๐น SUBQUERY vs CTE
๐น ISNULL vs COALESCE
๐น DELETE vs DROP
๐น INTERSECT vs INNER JOIN
๐น EXCEPT vs NOT IN
React โฅ๏ธ for detailed post with examples
Whether you're writing daily queries or preparing for interviews, understanding these subtle SQL differences can make a big impact on both performance and accuracy.
๐ง Hereโs a powerful visual that compares the most commonly misunderstood SQL concepts โ side by side.
๐ ๐๐ผ๐๐ฒ๐ฟ๐ฒ๐ฑ ๐ถ๐ป ๐๐ต๐ถ๐ ๐๐ป๐ฎ๐ฝ๐๐ต๐ผ๐:
๐น RANK() vs DENSE_RANK()
๐น HAVING vs WHERE
๐น UNION vs UNION ALL
๐น JOIN vs UNION
๐น CTE vs TEMP TABLE
๐น SUBQUERY vs CTE
๐น ISNULL vs COALESCE
๐น DELETE vs DROP
๐น INTERSECT vs INNER JOIN
๐น EXCEPT vs NOT IN
React โฅ๏ธ for detailed post with examples
โค10๐3๐1๐1
Useful websites to practice and enhance your Data Analytics skills
๐๐
1. SQL
https://mode.com/sql-tutorial/introduction-to-sql
https://t.iss.one/sqlspecialist/232?single
2. Python
https://www.learnpython.org/
https://bit.ly/3T7y4ta
https://www.geeksforgeeks.org/python-programming-language/learn-python-tutorial
3. R
https://www.datacamp.com/courses/free-introduction-to-r
4. Data Structures
https://leetcode.com/study-plan/data-structure/
5. Data Visualization
https://www.freecodecamp.org/learn/data-visualization/
https://www.tableau.com/learn/training/20223
https://www.workout-wednesday.com/power-bi-challenges/
6. Excel
https://excel-practice-online.com/
https://www.w3schools.com/EXCEL/index.php
Join @free4unow_backup for more free courses
ENJOY LEARNING ๐๐
๐๐
1. SQL
https://mode.com/sql-tutorial/introduction-to-sql
https://t.iss.one/sqlspecialist/232?single
2. Python
https://www.learnpython.org/
https://bit.ly/3T7y4ta
https://www.geeksforgeeks.org/python-programming-language/learn-python-tutorial
3. R
https://www.datacamp.com/courses/free-introduction-to-r
4. Data Structures
https://leetcode.com/study-plan/data-structure/
5. Data Visualization
https://www.freecodecamp.org/learn/data-visualization/
https://www.tableau.com/learn/training/20223
https://www.workout-wednesday.com/power-bi-challenges/
6. Excel
https://excel-practice-online.com/
https://www.w3schools.com/EXCEL/index.php
Join @free4unow_backup for more free courses
ENJOY LEARNING ๐๐
โค12
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