Data Analytics
Perfect channel to learn Data Analytics Learn SQL, Python, Alteryx, Tableau, Power BI and many more For Promotions: @coderfun @love_data
Показати більше📈 Аналітичний огляд Telegram-каналу Data Analytics
Канал Data Analytics (@sqlspecialist) у мовному сегменті Англійська є активним учасником. На даний момент спільнота об'єднує 110 799 підписників, посідаючи 1 072 місце в категорії Технології та додатки та 2 231 місце у регіоні Індія.
📊 Показники аудиторії та динаміка
З моменту свого створення невідомо, проект продемонстрував стрімке зростання, зібравши аудиторію у 110 799 підписників.
За останніми даними від 01 вересня, 2026, канал демонструє стабільну активність. Хоча за останні 30 днів спостерігається зміна кількості учасників на 213, а за останні 24 години на 0, загальне охоплення залишається високим.
- Статус верифікації: Не верифікований
- Рівень залученості (ER): Середній показник залученості аудиторії становить 2.87%. Протягом перших 24 годин після публікації контент зазвичай збирає 1.30% реакцій від загальної кількості підписників.
- Охоплення публікацій: В середньому кожен допис отримує 3 175 переглядів. Протягом першої доби публікація в середньому набирає 1 442 переглядів.
- Реакції та взаємодія: Аудиторія активно підтримує контент: середня кількість реакцій на один пост – 7.
- Тематичні інтереси: Контент зосереджений навколо ключових тем, таких як row, sql, analytic, analyst, visualization.
📝 Опис та контентна політика
Автор описує ресурс як майданчик для висловлення суб'єктивної думки:
“Perfect channel to learn Data Analytics
Learn SQL, Python, Alteryx, Tableau, Power BI and many more
For Promotions: @coderfun @love_data”
Завдяки високій частоті оновлень (останні дані отримано 02 вересня, 2026), канал підтримує актуальність та високий рівень охоплення публікацій. Аналітика показує, що аудиторія активно взаємодіє з контентом, що робить його важливою точкою впливу в категорії Технології та додатки.
"Give me all sales from the North region."Or:
"What was total revenue last month?"Or:
"Which 10 products generated the most revenue?"SQL allows you to ask these questions directly. 2️⃣ Why Is SQL Important for Data Analysts? Imagine a company has: 50 million transactions. Excel isn't the right tool for storing and querying all that information. The data may be stored in a database such as: • PostgreSQL • MySQL • Microsoft SQL Server • Oracle Database • Snowflake • BigQuery As a Data Analyst, you may connect to the database and use SQL to extract the data you need. A typical workflow looks like: Database ↓ SQL Query ↓ Required Data ↓ Analysis ↓ Dashboard / Report ↓ Business Decision 3️⃣ What Is a Database? A database is a system used to store and manage data. For example, an e-commerce company might have: • Customers • Products • Orders • Payments • Employees Each represents a different type of information. Instead of putting everything into one enormous table, relational databases typically organize related information into separate tables. 4️⃣ What Is a Table? A table is a structured collection of data organized into: Rows + Columns For example: Customers Customer_ID Customer_Name City 101 John Mumbai 102 Sarah Pune 103 Mike Delhi Each row represents one customer. Each column represents an attribute. This should look familiar from Excel. 5️⃣ Rows vs Columns Just like Excel: Row Represents a record. Example: 101 | John | Mumbai represents one customer. Column Represents an attribute. For example: • Customer_ID • Customer_Name • City A useful rule:
One row = one record One column = one attribute6️⃣ What Is a Primary Key? A Primary Key uniquely identifies each record in a table. For example: Customer_ID Customer_Name 101 John 102 Sarah 103 Mike Here: Customer_ID can be the primary key. Each customer should have a unique ID. 101 → John 102 → Sarah 103 → Mike You shouldn't have two different customers with the same primary key. 7️⃣ What Is a Foreign Key? A Foreign Key is a column used to establish a relationship between tables. Suppose: Customers Customer_ID Customer_Name 101 John 102 Sarah Orders Order_ID Customer_ID Sales 5001 101 50,000 5002 102 70,000 5003 101 30,000 Here: Customers.Customer_ID is the primary key. Orders.Customer_ID can be a foreign key.
Any number of characters.So this could match: • John • James • Jennifer 2️⃣3️⃣ LIKE with Wildcards • Starts with J LIKE 'J%' • Ends with n LIKE '%n' • Contains "oh" LIKE '%oh%' Wildcards are extremely useful when searching text data. 2️⃣4️⃣ DISTINCT DISTINCT removes duplicate values from the result. Suppose your employee table contains: • IT • HR • IT • Finance • HR • IT Use: SELECT DISTINCT Department FROM Employees; Result: IT HR Finance This is useful for discovering categories in a dataset. 2️⃣5️⃣ ORDER BY ORDER BY sorts your results. Suppose you want employees with the highest salary first. SELECT * FROM Employees ORDER BY Salary DESC; DESC means: Descending Highest → Lowest 2️⃣6️⃣ ASC ASC means ascending. SELECT * FROM Employees ORDER BY Salary ASC; Lowest → Highest Ascending is generally the default sort direction. 2️⃣7️⃣ LIMIT / TOP The syntax depends on the database system. In systems such as PostgreSQL and MySQL: SELECT * FROM Employees ORDER BY Salary DESC LIMIT 5; This returns the top 5 employees by salary. In SQL Server, you would commonly use: SELECT TOP 5 * FROM Employees ORDER BY Salary DESC; This is an important point:
SQL is a language, but different database systems have slightly different syntax.2️⃣8️⃣ Aliases Aliases give columns or tables temporary names within a query. For example: SELECT Name AS Employee_Name, Salary AS Annual_Salary FROM Employees; The result displays: Employee_Name Annual_Salary John 75,000 Sarah 60,000 Aliases make results easier to understand. 2️⃣9️⃣ SQL Comments You can add comments to explain your queries. For example: -- Get employees earning more than 70,000 SELECT Name, Salary FROM Employees WHERE Salary > 70000; Comments don't affect the query result. They're useful when queries become complex. 🧪 Practical Interview Challenge Suppose you have: Employees ID Name Department Salary 101 John IT 75,000 102 Sarah HR 60,000 103 Mike Finance 82,000 104 David IT 90,000 105 Alice HR 65,000 Q1. Retrieve all employees. SELECT * FROM Employees; Q2. Retrieve only names and salaries. SELECT Name, Salary FROM Employees; Q3. Find employees earning more than ₹70,000. SELECT * FROM Employees WHERE Salary > 70000; Q4. Find IT employees. SELECT * FROM Employees WHERE Department = 'IT'; Q5. Find IT or Finance employees. SELECT * FROM Employees WHERE Department IN ('IT', 'Finance'); Q6. Sort employees by salary from highest to lowest. SELECT * FROM Employees ORDER BY Salary DESC; Q7. Find the top 3 highest-paid employees. PostgreSQL/MySQL: SELECT * FROM Employees ORDER BY Salary DESC LIMIT 3; SQL Server: SELECT TOP 3 * FROM Employees ORDER BY Salary DESC; Q8. List unique departments. SELECT DISTINCT Department FROM Employees; 🏆 Double Tap ❤️ For More ----- 1.59 ₽ · /balance_help
Return all columns from the Customers table.Let me break it down. SELECT: Specifies what you want to retrieve. FROM: Specifies the table. Customers: The table you're querying. 1️⃣1️⃣ SELECT SELECT is one of the first SQL commands you need to learn. Suppose you have: Employees Employee_ID Name Department Salary 101 John IT 75,000 102 Sarah HR 60,000 103 Mike Finance 82,000 To retrieve all columns: SELECT * FROM Employees; 1️⃣2️⃣ Selecting Specific Columns You don't always need every column. Suppose you only want: Name and Department Use: SELECT Name, Department FROM Employees; Result: Name Department John IT Sarah HR Mike Finance This is generally better than using SELECT * when you only need specific fields. 1️⃣3️⃣ Why Avoid SELECT * in Production Queries? You may see beginners writing: SELECT * FROM Employees; all the time. It's useful while learning and exploring data. But in production queries, explicitly selecting the required columns is often better because: • It makes the query clearer • It avoids retrieving unnecessary data • It can reduce data transfer • It makes downstream dependencies more predictable For example: SELECT Employee_ID, Name, Salary FROM Employees; is more intentional. 1️⃣4️⃣ WHERE WHERE filters records. Suppose you want employees from IT. SELECT * FROM Employees WHERE Department = 'IT'; Result: Employee_ID Name Department Salary 101 John IT 75,000 The database only returns records satisfying the condition. 1️⃣5️⃣ Filtering Numeric Values Suppose you want employees earning more than ₹70,000. SELECT * FROM Employees WHERE Salary > 70000; Result: Employee_ID Name Department Salary 101 John IT 75,000 103 Mike Finance 82,000 1️⃣6️⃣ Comparison Operators You should know these operators: Operator Meaning = Equal to <> Not equal to
Greater than < Less than = Greater than or equal <= Less than or equalExamples: WHERE Salary >= 80000 WHERE Department <> 'HR' 1️⃣7️⃣ AND AND requires all conditions to be true. Suppose you want: IT employees earning more than ₹70,000. SELECT * FROM Employees WHERE Department = 'IT' AND Salary > 70000; The record must satisfy both conditions. Think: IT AND Salary > 70,000 1️⃣8️⃣ OR OR requires at least one condition to be true. Suppose you want: IT or Finance employees.
"Give me all sales from the North region."Or:
"What was total revenue last month?"Or:
"Which 10 products generated the most revenue?"SQL allows you to ask these questions directly. 2️⃣ Why Is SQL Important for Data Analysts? Imagine a company has: 50 million transactions. Excel isn't the right tool for storing and querying all that information. The data may be stored in a database such as: • PostgreSQL • MySQL • Microsoft SQL Server • Oracle Database • Snowflake • BigQuery As a Data Analyst, you may connect to the database and use SQL to extract the data you need. A typical workflow looks like: Database ↓ SQL Query ↓ Required Data ↓ Analysis ↓ Dashboard / Report ↓ Business Decision 3️⃣ What Is a Database? A database is a system used to store and manage data. For example, an e-commerce company might have: • Customers • Products • Orders • Payments • Employees Each represents a different type of information. Instead of putting everything into one enormous table, relational databases typically organize related information into separate tables. 4️⃣ What Is a Table? A table is a structured collection of data organized into: Rows + Columns For example: Customers Customer_ID Customer_Name City 101 John Mumbai 102 Sarah Pune 103 Mike Delhi Each row represents one customer. Each column represents an attribute. This should look familiar from Excel. 5️⃣ Rows vs Columns Just like Excel: Row Represents a record. Example: 101 | John | Mumbai represents one customer. Column Represents an attribute. For example: • Customer_ID • Customer_Name • City A useful rule:
One row = one record One column = one attribute6️⃣ What Is a Primary Key? A Primary Key uniquely identifies each record in a table. For example: Customer_ID Customer_Name 101 John 102 Sarah 103 Mike Here: Customer_ID can be the primary key. Each customer should have a unique ID. 101 → John 102 → Sarah 103 → Mike You shouldn't have two different customers with the same primary key. 7️⃣ What Is a Foreign Key? A Foreign Key is a column used to establish a relationship between tables. Suppose: Customers Customer_ID Customer_Name 101 John 102 Sarah Orders Order_ID Customer_ID Sales 5001 101 50,000 5002 102 70,000 5003 101 30,000 Here: Customers.Customer_ID is the primary key. Orders.Customer_ID can be a foreign key.
The data is often messy.You might receive a monthly Excel file with: • Duplicate records • Missing values • Incorrect data types • Extra spaces • Inconsistent names • Multiple files • Unnecessary columns • Data spread across different tables Cleaning this manually every time is slow and error-prone. That's where Power Query comes in. 1️⃣ What Is Power Query? Power Query is a data preparation and transformation tool available in Excel and Power BI. It allows you to: Connect → Extract → Transform → Load - This is commonly called ETL. Extract: Get data from a source. Transform: Clean and reshape the data. Load: Bring the prepared data into Excel for analysis. The biggest advantage is repeatability. Instead of cleaning the same file manually every month, you create a transformation process once and refresh it. 2️⃣ Why Should a Data Analyst Learn Power Query? Imagine your company sends you this file every month: January.xlsx, February.xlsx, March.xlsx, April.xlsx... Every file contains 50,000 rows, extra spaces, duplicates, incorrect date formats. Without Power Query, you repeat the same cleaning every month. With Power Query: Refresh → Transformations run again 3️⃣ Where Do You Find Power Query? In modern Excel: Data → Get & Transform Data Options: From Table/Range, From Workbook, From Text/CSV, From Folder, From Web, From Database 4️⃣ Understand the Power Query Workflow Data Source → Connect → Power Query Editor → Clean → Transform → Validate → Load → Excel / Data Model → Analysis Power Query records the transformation steps. 5️⃣ Import Data from Excel & CSV Excel: Data → Get Data → From File → From Excel Workbook → Select sheet → Open in Power Query Editor CSV: Data → From Text/CSV → Preview delimiter, headers, data types → Transform Data 6️⃣ Power Query Editor Left side: Queries Middle: Data preview Right side: Applied Steps Example Applied Steps: Source → Changed Type → Removed Columns → Filtered Rows → Removed Duplicates → Renamed Columns → Added Custom Column 7️⃣ Changing Data Types Correct data types are critical. Order ID → Whole Number, Order Date → Date, Sales → Decimal Number, Customer → Text Use the data-type icon to change it. 8️⃣ Remove Duplicates If Order ID should be unique, select the column and use: Remove Rows → Remove Duplicates 🔟 Important: Understand What a Duplicate Means Don't automatically delete duplicates. Ask: > Is this actually a duplicate? Two records with same customer but different orders = Not a duplicate. Same order appearing twice = Duplicate. 1️⃣1️⃣ Remove & Rename Columns Remove unnecessary columns: Home → Remove Columns Rename for clarity: CustNm → Customer Name, SlsAmt → Sales 1️⃣2️⃣ Filter Rows Filtering in Power Query becomes part of the reusable query. Example: Keep only orders from 2026, or North region, or Sales > 0 1️⃣3️⃣ Handle Missing Values Never blindly replace missing values with zero.
How many orders were placed in January? How long did customers wait for delivery? Which month had the highest sales? How many days overdue are invoices? How many years has an employee worked?To answer these questions, you need to understand Excel's date and time functions. 1️⃣ How Excel Stores Dates One important concept is that Excel stores dates as numbers internally. For example, a date such as: 01-Jan-2026 is represented internally by a serial number. This is why Excel can perform calculations such as: =B2-A2 If: A2 = 01-Jan-2026, B2 = 10-Jan-2026 the result can be: 9 meaning 9 days between the dates. This is the foundation of date calculations in Excel. 2️⃣ TODAY() TODAY() returns the current date. =TODAY() For example, if today's date is August 25, 2026, Excel returns: 25-Aug-2026 The value automatically changes when the date changes. Common uses: Employee tenure, Age calculations, Overdue invoices, Days remaining, Current reporting period, Aging analysis 3️⃣ NOW() NOW() returns the current date and time. =NOW() Example: 25-Aug-2026 01:38 The exact result depends on when Excel recalculates. TODAY vs NOW: TODAY() → Current date, NOW() → Current date + current time 4️⃣ DATE() DATE() creates a valid Excel date from year, month and day. =DATE(2026,8,25) Result: 25-Aug-2026 This is useful when dates need to be constructed from separate columns. For example: Year: 2026, Month: 8, Day: 25 - You can create the date with: =DATE(A2,B2,C2) 5️⃣ YEAR() YEAR() extracts the year from a date. Suppose: A2 = 25-Aug-2026 Use: =YEAR(A2) Result: 2026 Common uses: Yearly reporting, Year-over-year analysis, Creating Year columns, Grouping transactions by year 6️⃣ MONTH() MONTH() extracts the month number. =MONTH(A2) For: 25-Aug-2026 the result is: 8 because August is the eighth month. 7️⃣ DAY() DAY() extracts the day of the month. =DAY(A2) For: 25-Aug-2026 result: 25 8️⃣ Create Year, Month and Day Columns Suppose you have: Order Date - 15-Jan-2026, 20-Feb-2026, 10-Mar-2026 You can create: Year: =YEAR(A2), Month Number: =MONTH(A2), Day: =DAY(A2) This can help you analyze data by different time periods. 9️⃣ EOMONTH() EOMONTH() returns the last day of a month. Syntax: =EOMONTH(start_date,months) Suppose: A2 = 15-Aug-2026 Use: =EOMONTH(A2,0) Result: 31-Aug-2026 Next month's end: =EOMONTH(A2,1) Result: 30-Sep-2026 Previous month's end: =EOMONTH(A2,-1) Result: 31-Jul-2026 🔟 Why EOMONTH() Is Useful It's extremely useful for: Month-end reporting, Financial reporting, Invoice analysis, Aging reports, Monthly dashboards, Closing processes For example: "Give me all transactions up to the end of the reporting month." EOMONTH() becomes very useful here. 1️⃣1️⃣ EDATE() EDATE() moves a date forward or backward by a specified number of months. Suppose: A2 = 25-Aug-2026
=TRIM(A2)
Task 2 — Convert to proper case
=PROPER(TRIM(A2))
Task 3 — Count characters
=LEN(A2)
Task 4 — Convert to uppercase
=UPPER(A2)
Task 5 — Extract the first 3 characters
=LEFT(A2,3)
🏆 Key Lesson
Text functions aren't just about manipulating words.
For a Data Analyst, they're data-cleaning tools.
When you receive messy data, think:
Remove unwanted spaces → Standardize → Extract → Replace → Combine → Validate
For example:
=PROPER(TRIM(A2))
can turn:
" jOhN sMiTh "
into:
John Smith
That may look like a small task, but cleaning and standardizing data correctly is an important part of professional analytics.
Double Tap ❤️ For Part-7
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2.31 ₽ · /balance_help=MID(text,start_num,num_chars)Suppose: EMP-001-IND You want: 001 Use:
=MID(A2,5,3)Result: 001 Because: Start at character 5 Extract 3 characters 🔟 FIND() FIND() tells you where one piece of text appears inside another. Example: john.smith@gmail.com You can find the position of @:
=FIND("@",A2)
This returns the position of the @ character.
Why is this useful?
You can use the position to extract:
• Email username
• Domain
• Product components
• Codes
• Identifiers
1️⃣1️⃣ SEARCH()
SEARCH() is similar to FIND() but has some differences.
For example:
=SEARCH("india",A2)
Unlike FIND(), SEARCH() is not case-sensitive.
Simple distinction:
FIND() → Case-sensitive
SEARCH() → Not case-sensitive
This difference can matter when cleaning real-world data.
1️⃣2️⃣ SUBSTITUTE()
SUBSTITUTE() replaces specific text with another value.
Suppose:
A2 = Mumbai, India
You want to replace the comma with a hyphen.
=SUBSTITUTE(A2,",","-")Result: Mumbai- India You can also replace words.
=SUBSTITUTE(A2,"India","IND")Result: Mumbai, IND 1️⃣3️⃣ CONCAT() CONCAT() combines text. Suppose: First Name | Last Name John | Smith Formula:
=CONCAT(A2," ",B2)Result: John Smith This is useful when you need to create: • Full names • IDs • Labels • Descriptions 1️⃣4️⃣ TEXTJOIN() TEXTJOIN() is particularly useful when combining multiple values with a delimiter. Example: Suppose: A2 = John B2 = Smith C2 = India Formula:
=TEXTJOIN(", ",TRUE,A2:C2)
Result:
John, Smith, India
The second argument:
TRUE
tells Excel to ignore empty cells.
1️⃣5️⃣ TEXTSPLIT()
Modern Excel includes TEXTSPLIT(), which is extremely useful for breaking text into multiple columns.
Suppose:
A2 = John,IT,Pune
Use:
=TEXTSPLIT(A2,",")Excel can split it into: John | IT | Pune This is particularly useful when data arrives in a delimited format. 1️⃣6️⃣ Extract an Email Username Suppose: A2 = john.smith@gmail.com You want: john.smith Using modern Excel:
=TEXTBEFORE(A2,"@")Result: john.smith 1️⃣7️⃣ Extract an Email Domain Using the same data: john.smith@gmail.com Use:
=TEXTAFTER(A2,"@")Result: gmail.com These modern text functions can make data preparation much easier. 1️⃣8️⃣ Combining Text Functions The real power comes from combining functions. Suppose your data contains: " JOHN SMITH " You want: John Smith You could use:
=PROPER(TRIM(A2))First: TRIM() removes unnecessary spaces. Then: PROPER() formats the name. Result: John Smith 1️⃣9️⃣ Real-World Data Cleaning Example Suppose your department column contains: IT IT it IT It These values may represent the same department. You could standardize them with:
=UPPER(TRIM(A2))Results become: IT IT IT IT IT Now filtering, counting and lookups become much more reliable. 2️⃣0️⃣ Data Quality Check Using Text Functions Suppose all employee IDs should contain exactly 6 characters. You can use:
=IF(LEN(A2)=6,"Valid","Check")If: A2 = EMP001 Result: Valid If: A2 = EMP01 Result: Check This is a simple example of using Excel for data-quality validation. 🧪 Practical Interview Challenge
=TRIM(A2)
Why is this important?
Suppose you have:
IT
IT
IT
IT
They may look identical, but hidden spaces can cause lookup and filtering problems.
For example:
=XLOOKUP("IT",A2:A100,B2:B100)
may not behave as expected if the underlying values contain unwanted spaces.
Data Analyst use cases:
Use TRIM() for:
• Customer names
• Department names
• Product names
• Country names
• Category values
2️⃣ CLEAN()
CLEAN() removes many non-printing characters from text.
Formula:
=CLEAN(A2)
This can be useful when data is copied from:
• Websites
• External systems
• Reports
• PDFs
• Legacy applications
Sometimes invisible characters are present even though the text looks normal.
TRIM vs CLEAN:
TRIM() → Removes unnecessary spaces.
CLEAN() → Removes non-printing characters.
You can combine them:
=TRIM(CLEAN(A2))
This is a very useful basic data-cleaning pattern.
3️⃣ UPPER()
Converts text to uppercase.
=UPPER(A2)
Example:
india
becomes:
INDIA
Why use it?
Suppose your dataset contains:
India
india
INDIA
You can standardize them using:
=UPPER(A2)
Now they all become:
INDIA
4️⃣ LOWER()
Converts text to lowercase.
=LOWER(A2)
Example:
JOHN.SMITH@EMAIL.COM
becomes:
john.smith@email.com
This is particularly useful for standardizing:
• Email addresses
• Usernames
• IDs
• Text categories
——————————
5️⃣ PROPER()
Converts text into proper case.
=PROPER(A2)
Example:
john smith
becomes:
John Smith
And:
mumbai
becomes:
Mumbai
Important:
PROPER() is useful for presentation, but don't automatically use it for every dataset.
Some names, product codes, or abbreviations should remain uppercase.
For example:
IBM
SQL
USA
may become undesirable results if automatically converted to proper case.
6️⃣ LEN()
LEN() returns the number of characters in a text string.
=LEN(A2)
Example:
A2 = "John"
Result:
4
Why is this useful?
It can help identify:
• Invalid IDs
• Incorrect phone numbers
• Unexpected text lengths
• Data-quality issues
For example:
Employee IDs should always contain 6 characters.You could check:
=IF(LEN(A2)=6,"Valid","Check")
7️⃣ LEFT()
LEFT() extracts characters from the beginning of a text string.
Syntax:
=LEFT(text,num_chars)
Example:
EMP-001-IND
To extract the first three characters:
=LEFT(A2,3)
Result:
EMP
8️⃣ RIGHT()
RIGHT() extracts characters from the end of a text string.
Example:
EMP-001-IND
Formula:
=RIGHT(A2,3)
Result:
IND
This can be useful for extracting:
• Country codes
• File extensions
• Product suffixes
• Transaction codes
9️⃣ MID()