COMMON SQL TERMINOLOGIES - PART 1
In this series, we'll explore the common terminologies in SQL to help you navigate the world of databases.
Here are a few SQL terminologies to get you started:
SQL (Structured Query Language)
A programming language designed for managing and querying data in relational databases.
Database
A structured collection of data stored and organized to allow for easy access, retrieval, and management. Example: MySQL, PostgreSQL, SQL Server.
Table
A collection of data organized into rows and columns within a database. Think of it as a spreadsheet in Excel.
Example:
| ID | Name | Age |
|----|-----------|-----|
| 1 | John Doe | 25 |
| 2 | Jane Smith| 30 |
Row (or Record)
A single entry in a table that contains data for all columns in that table.
Example: 1, 'John Doe', 25
Column (or Field)
A specific attribute or property in a table. Each column contains data of the same type.
Example: Columns in a "users" table might include ID, Name, and Age.
Query
A statement written in SQL to perform a specific task, such as retrieving, updating, or deleting data.
Example: SELECT * FROM users;
Primary Key
A unique identifier for each record in a table. It ensures that no two rows have the same key value.
Example: The ID column in a table is often the primary key.
Foreign Key
A field in a table that links to the primary key in another table, establishing a relationship between the two tables.
Example: In an "Orders" table, a CustomerID might link to the ID in a "Customers" table.
Index
A performance optimization feature that allows quick retrieval of rows from a table based on column values.
Clause
A part of an SQL statement that performs a specific task, like filtering, grouping, or sorting data.
Examples:
WHERE: Filters records based on conditions.
GROUP BY: Groups data based on a column.
Result Set
The output of a query, typically in tabular form.
Example:
After running SELECT Name FROM users;, the result set might look like:
| Name |
|------------|
| John Doe |
| Jane Smith |
Join
A method to combine rows from two or more tables based on a related column.
Example:
Aggregate Function
A function that performs a calculation on a group of values and returns a single value.
Examples:
SUM: Adds values.
AVG: Calculates the average.
COUNT: Counts the number of rows.
Script
A file containing a series of SQL commands that can be executed together.
Example: A .sql file with multiple CREATE, INSERT, or SELECT statements.
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#sql
In this series, we'll explore the common terminologies in SQL to help you navigate the world of databases.
Here are a few SQL terminologies to get you started:
SQL (Structured Query Language)
A programming language designed for managing and querying data in relational databases.
Database
A structured collection of data stored and organized to allow for easy access, retrieval, and management. Example: MySQL, PostgreSQL, SQL Server.
Table
A collection of data organized into rows and columns within a database. Think of it as a spreadsheet in Excel.
Example:
| ID | Name | Age |
|----|-----------|-----|
| 1 | John Doe | 25 |
| 2 | Jane Smith| 30 |
Row (or Record)
A single entry in a table that contains data for all columns in that table.
Example: 1, 'John Doe', 25
Column (or Field)
A specific attribute or property in a table. Each column contains data of the same type.
Example: Columns in a "users" table might include ID, Name, and Age.
Query
A statement written in SQL to perform a specific task, such as retrieving, updating, or deleting data.
Example: SELECT * FROM users;
Primary Key
A unique identifier for each record in a table. It ensures that no two rows have the same key value.
Example: The ID column in a table is often the primary key.
Foreign Key
A field in a table that links to the primary key in another table, establishing a relationship between the two tables.
Example: In an "Orders" table, a CustomerID might link to the ID in a "Customers" table.
Index
A performance optimization feature that allows quick retrieval of rows from a table based on column values.
Clause
A part of an SQL statement that performs a specific task, like filtering, grouping, or sorting data.
Examples:
WHERE: Filters records based on conditions.
GROUP BY: Groups data based on a column.
Result Set
The output of a query, typically in tabular form.
Example:
After running SELECT Name FROM users;, the result set might look like:
| Name |
|------------|
| John Doe |
| Jane Smith |
Join
A method to combine rows from two or more tables based on a related column.
Example:
SELECT orders.id, customers.name FROM orders JOIN customers ON orders.customer_id = customers.id;
Aggregate Function
A function that performs a calculation on a group of values and returns a single value.
Examples:
SUM: Adds values.
AVG: Calculates the average.
COUNT: Counts the number of rows.
Script
A file containing a series of SQL commands that can be executed together.
Example: A .sql file with multiple CREATE, INSERT, or SELECT statements.
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COMMON TERMINOLOGIES IN SQL - PART 2
Schema
A blueprint or structure of a database that defines how data is organized, including tables, views, and relationships.
Example: In a library database, the schema might define tables like Books, Authors, and Borrowers.
View
A virtual table created from the result of a SQL query. It doesn't store data but dynamically pulls it from the underlying tables.
Example:
Alias
A temporary name assigned to a table or column to make queries more readable.
Example:
Transaction
A sequence of one or more SQL operations performed as a single unit of work. If one part fails, the entire transaction is rolled back.
Commands:
BEGIN TRANSACTION: Starts a transaction
COMMIT: Saves changes
ROLLBACK: Reverts changes
Normalization
The process of organizing data to reduce redundancy and improve data integrity by dividing data into related tables.
Forms:
1NF (First Normal Form): Ensures no repeating groups
2NF (Second Normal Form): Removes partial dependencies
3NF (Third Normal Form): Removes transitive dependencies
Denormalization
The process of combining tables to improve query performance, often at the cost of redundancy.
Constraint
A rule applied to a table's columns to enforce data integrity.
Examples:
NOT NULL: Ensures a column cannot have a NULL value
UNIQUE: Ensures all values in a column are unique
CHECK: Ensures column values meet a specific condition
DEFAULT: Provides a default value for a column
Stored Procedure
A reusable, precompiled set of SQL statements stored in the database.
Example:
Trigger
A set of SQL instructions automatically executed in response to certain events (INSERT, UPDATE, DELETE) on a table.
Example:
Cursor
A database object used to retrieve, manipulate, and navigate through a result set row by row.
Example:
Subquery
A query nested inside another SQL query to provide intermediate results.
Example:
Indexing
A technique to speed up data retrieval by creating a data structure that allows the database to find rows faster.
Example:
Wildcards
Special characters used in LIKE queries for pattern matching.
Examples:
%: Represents zero or more characters
ACID Properties
Set of properties ensuring database reliability in transactions:
Atomicity: All tasks are completed or none are
Consistency: Ensures data integrity before and after a transaction
Isolation: Transactions do not interfere with each other
Durability: Changes persist even in the event of a failure
Common Table Expression (CTE)
A temporary, named result set used within a query.
Example:
Partitioning
Dividing a table into smaller, more manageable pieces for performance optimization.
Example: Range-based partitioning by year
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Schema
A blueprint or structure of a database that defines how data is organized, including tables, views, and relationships.
Example: In a library database, the schema might define tables like Books, Authors, and Borrowers.
View
A virtual table created from the result of a SQL query. It doesn't store data but dynamically pulls it from the underlying tables.
Example:
CREATE VIEW ActiveUsers AS
SELECT Name, Email
FROM Users
WHERE Status = 'Active';
Alias
A temporary name assigned to a table or column to make queries more readable.
Example:
SELECT u.Name AS UserName, o.OrderDate
FROM Users u
JOIN Orders o ON u.ID = o.UserID;
Transaction
A sequence of one or more SQL operations performed as a single unit of work. If one part fails, the entire transaction is rolled back.
Commands:
BEGIN TRANSACTION: Starts a transaction
COMMIT: Saves changes
ROLLBACK: Reverts changes
Normalization
The process of organizing data to reduce redundancy and improve data integrity by dividing data into related tables.
Forms:
1NF (First Normal Form): Ensures no repeating groups
2NF (Second Normal Form): Removes partial dependencies
3NF (Third Normal Form): Removes transitive dependencies
Denormalization
The process of combining tables to improve query performance, often at the cost of redundancy.
Constraint
A rule applied to a table's columns to enforce data integrity.
Examples:
NOT NULL: Ensures a column cannot have a NULL value
UNIQUE: Ensures all values in a column are unique
CHECK: Ensures column values meet a specific condition
DEFAULT: Provides a default value for a column
Stored Procedure
A reusable, precompiled set of SQL statements stored in the database.
Example:
CREATE PROCEDURE GetActiveUsers()
AS
BEGIN
SELECT * FROM Users WHERE Status = 'Active';
END;
Trigger
A set of SQL instructions automatically executed in response to certain events (INSERT, UPDATE, DELETE) on a table.
Example:
CREATE TRIGGER LogChanges
AFTER UPDATE ON Users
FOR EACH ROW
INSERT INTO AuditLog(UserID, ChangeDate) VALUES (NEW.ID, NOW());
Cursor
A database object used to retrieve, manipulate, and navigate through a result set row by row.
Example:
DECLARE CursorExample CURSOR FOR
SELECT Name FROM Users;
OPEN CursorExample;
FETCH NEXT FROM CursorExample;
Subquery
A query nested inside another SQL query to provide intermediate results.
Example:
SELECT Name FROM Users
WHERE ID IN (SELECT UserID FROM Orders WHERE OrderDate > '2024-01-01');
Indexing
A technique to speed up data retrieval by creating a data structure that allows the database to find rows faster.
Example:
CREATE INDEX idx_username ON Users (Name);
Wildcards
Special characters used in LIKE queries for pattern matching.
Examples:
%: Represents zero or more characters
SELECT * FROM Users WHERE Name LIKE 'J%';
_: Represents a single character
SELECT * FROM Users WHERE Name LIKE 'J_n';
ACID Properties
Set of properties ensuring database reliability in transactions:
Atomicity: All tasks are completed or none are
Consistency: Ensures data integrity before and after a transaction
Isolation: Transactions do not interfere with each other
Durability: Changes persist even in the event of a failure
Common Table Expression (CTE)
A temporary, named result set used within a query.
Example:
WITH ActiveUsers AS (
SELECT Name, Email FROM Users WHERE Status = 'Active'
)
SELECT * FROM ActiveUsers;
Partitioning
Dividing a table into smaller, more manageable pieces for performance optimization.
Example: Range-based partitioning by year
CREATE TABLE Sales_2024 PARTITION OF Sales FOR VALUES FROM ('2024-01-01') TO ('2024-12-31');I've curated essential SQL Interview Resources👇
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COMMON TERMINOLOGIES IN POWER BI - PART 1
Let’s explore some basic Power BI terminologies to help you get familiar with this powerful data visualization tool.
Dashboard
A single page, interactive report showing a summarized view of your data. Dashboards can include visuals from multiple reports but are limited to one page.
Report
A collection of visuals, like charts, graphs, and tables, spread across multiple pages, offering in-depth insights into your data.
Workspace
A shared environment in Power BI where you can collaborate with team members to create, share, and manage dashboards and reports.
Dataset
A collection of data that you import or connect to in Power BI, which serves as the foundation for creating visuals and reports.
Data Source
The origin of the data you're analyzing in Power BI. It could be Excel, SQL Server, SharePoint, or online services like Google Analytics.
Query Editor
The tool in Power BI used to clean, transform, and shape your raw data before creating visuals. It's part of Power Query.
Power Query
A data connection and transformation tool in Power BI that helps you prepare data for analysis.
Data Model
The underlying structure in Power BI that defines how data is organized and related to other tables.
Measure
A calculated value created using DAX (Data Analysis Expressions). Measures are used to perform calculations on your data dynamically.
Example: Total Sales = SUM(Sales[Amount])
Calculated Column
A column created in Power BI using DAX formulas, often based on other columns in the table.
Example: Profit Margin = Sales[Profit] / Sales[Revenue]
Relationship
The connection between two tables in a data model, typically defined by matching a column in one table to a column in another. Relationships can be one-to-one, one-to-many, or many-to-many.
DAX (Data Analysis Expressions)
The formula language in Power BI used to create measures, calculated columns, and custom calculations.
Visualization
A graphical representation of data, such as a bar chart, pie chart, or map, used to analyze and interpret data trends.
Filter
A tool to narrow down the data displayed in your report or visual based on specific conditions. Filters can be applied at different levels: visual, page, or report.
Slicer
A special visual in Power BI that acts as an interactive filter, allowing users to dynamically filter data in reports.
Drillthrough
A feature in Power BI that enables users to navigate to a detailed page or report for more in-depth analysis of specific data points.
Power BI Service
The online cloud-based platform for sharing and collaborating on dashboards, reports, and datasets.
Gateway
A bridge that connects on-premises data sources to the Power BI service, enabling real-time data refresh.
Refresh
The process of updating your data in Power BI to reflect the most recent changes in the underlying data source.
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Let’s explore some basic Power BI terminologies to help you get familiar with this powerful data visualization tool.
Dashboard
A single page, interactive report showing a summarized view of your data. Dashboards can include visuals from multiple reports but are limited to one page.
Report
A collection of visuals, like charts, graphs, and tables, spread across multiple pages, offering in-depth insights into your data.
Workspace
A shared environment in Power BI where you can collaborate with team members to create, share, and manage dashboards and reports.
Dataset
A collection of data that you import or connect to in Power BI, which serves as the foundation for creating visuals and reports.
Data Source
The origin of the data you're analyzing in Power BI. It could be Excel, SQL Server, SharePoint, or online services like Google Analytics.
Query Editor
The tool in Power BI used to clean, transform, and shape your raw data before creating visuals. It's part of Power Query.
Power Query
A data connection and transformation tool in Power BI that helps you prepare data for analysis.
Data Model
The underlying structure in Power BI that defines how data is organized and related to other tables.
Measure
A calculated value created using DAX (Data Analysis Expressions). Measures are used to perform calculations on your data dynamically.
Example: Total Sales = SUM(Sales[Amount])
Calculated Column
A column created in Power BI using DAX formulas, often based on other columns in the table.
Example: Profit Margin = Sales[Profit] / Sales[Revenue]
Relationship
The connection between two tables in a data model, typically defined by matching a column in one table to a column in another. Relationships can be one-to-one, one-to-many, or many-to-many.
DAX (Data Analysis Expressions)
The formula language in Power BI used to create measures, calculated columns, and custom calculations.
Visualization
A graphical representation of data, such as a bar chart, pie chart, or map, used to analyze and interpret data trends.
Filter
A tool to narrow down the data displayed in your report or visual based on specific conditions. Filters can be applied at different levels: visual, page, or report.
Slicer
A special visual in Power BI that acts as an interactive filter, allowing users to dynamically filter data in reports.
Drillthrough
A feature in Power BI that enables users to navigate to a detailed page or report for more in-depth analysis of specific data points.
Power BI Service
The online cloud-based platform for sharing and collaborating on dashboards, reports, and datasets.
Gateway
A bridge that connects on-premises data sources to the Power BI service, enabling real-time data refresh.
Refresh
The process of updating your data in Power BI to reflect the most recent changes in the underlying data source.
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COMMON TABLEAU TERMINOLOGIES - PART 1
Today, Let’s explore some essential Tableau terms to help you understand and use this powerful data visualization tool more effectively.
Workbook
A file in Tableau that contains all the dashboards, sheets, and data connections for your analysis.
Sheet
A single workspace in Tableau where you create a specific visualization, like a chart, graph, or map.
Dashboard
A collection of multiple sheets displayed together, allowing you to create an interactive, multi-visualization view of your data.
Story
A sequence of dashboards or sheets that provides a narrative or walkthrough of your data insights.
Data Source
The origin of the data you connect to in Tableau, such as Excel files, databases, or web services.
Dimensions
Qualitative or categorical fields that describe the data (e.g., Product Names, Regions). They are typically used for grouping or filtering data.
Measures
Quantitative fields (numeric data) that can be aggregated (e.g., Sales, Profit). Measures are used for calculations and visual analysis.
Fields
Columns in your data source that Tableau uses as dimensions or measures.
Filter
A tool to narrow down data displayed in your visualization based on specific conditions.
Marks
The individual data points in a visualization, such as bars in a bar chart or dots in a scatter plot.
Pages
A feature in Tableau that allows you to break down your visualizations into separate pages based on a field value for detailed analysis.
Tooltip
A pop-up box displaying additional information about a mark when you hover over it in a visualization.
Pane
The area within a visualization that contains rows and columns of data.
Axis
The lines representing data values in charts, such as the X-axis (horizontal) and Y-axis (vertical).
Hierarchy
A structured arrangement of dimensions for drilling down into more granular data.
Example: Category → Sub-Category → Product
Filters Shelf
A section in Tableau where you add fields to apply filters to your data.
Rows and Columns Shelves
The areas in Tableau where you drag fields to determine how data is arranged in your visualization.
Aggregations
The summarization of data into a single value, like SUM, AVG, COUNT, or MAX.
Calculated Field
A custom field created using formulas to derive new insights or metrics from your existing data.
Measure Names
A special field in Tableau that contains the names of all measures in your data source.
Measure Values
A special field that holds the values of all the measures in your data source.
Color Shelf
An option in Tableau to assign colors to different fields or values for better visual distinction.
Size Shelf
An option to adjust the size of marks based on a field value.
Shape Shelf
An option to change the shape of marks based on specific field values.
Sorting
Organizing data in ascending or descending order within a visualization.
Blending
Combining data from two or more data sources in Tableau based on a common field.
Joins
Combining tables from the same data source using relationships like INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN.
Resources to learn Tableau
Data Analyst Checklist
Like this post if you want me to continue this Tableau series 👍♥️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
Today, Let’s explore some essential Tableau terms to help you understand and use this powerful data visualization tool more effectively.
Workbook
A file in Tableau that contains all the dashboards, sheets, and data connections for your analysis.
Sheet
A single workspace in Tableau where you create a specific visualization, like a chart, graph, or map.
Dashboard
A collection of multiple sheets displayed together, allowing you to create an interactive, multi-visualization view of your data.
Story
A sequence of dashboards or sheets that provides a narrative or walkthrough of your data insights.
Data Source
The origin of the data you connect to in Tableau, such as Excel files, databases, or web services.
Dimensions
Qualitative or categorical fields that describe the data (e.g., Product Names, Regions). They are typically used for grouping or filtering data.
Measures
Quantitative fields (numeric data) that can be aggregated (e.g., Sales, Profit). Measures are used for calculations and visual analysis.
Fields
Columns in your data source that Tableau uses as dimensions or measures.
Filter
A tool to narrow down data displayed in your visualization based on specific conditions.
Marks
The individual data points in a visualization, such as bars in a bar chart or dots in a scatter plot.
Pages
A feature in Tableau that allows you to break down your visualizations into separate pages based on a field value for detailed analysis.
Tooltip
A pop-up box displaying additional information about a mark when you hover over it in a visualization.
Pane
The area within a visualization that contains rows and columns of data.
Axis
The lines representing data values in charts, such as the X-axis (horizontal) and Y-axis (vertical).
Hierarchy
A structured arrangement of dimensions for drilling down into more granular data.
Example: Category → Sub-Category → Product
Filters Shelf
A section in Tableau where you add fields to apply filters to your data.
Rows and Columns Shelves
The areas in Tableau where you drag fields to determine how data is arranged in your visualization.
Aggregations
The summarization of data into a single value, like SUM, AVG, COUNT, or MAX.
Calculated Field
A custom field created using formulas to derive new insights or metrics from your existing data.
Measure Names
A special field in Tableau that contains the names of all measures in your data source.
Measure Values
A special field that holds the values of all the measures in your data source.
Color Shelf
An option in Tableau to assign colors to different fields or values for better visual distinction.
Size Shelf
An option to adjust the size of marks based on a field value.
Shape Shelf
An option to change the shape of marks based on specific field values.
Sorting
Organizing data in ascending or descending order within a visualization.
Blending
Combining data from two or more data sources in Tableau based on a common field.
Joins
Combining tables from the same data source using relationships like INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN.
Resources to learn Tableau
Data Analyst Checklist
Like this post if you want me to continue this Tableau series 👍♥️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
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Many people pay too much to learn SQL, but my mission is to break down barriers. I have shared complete learning series to learn SQL from scratch.
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Complete SQL Topics for Data Analyst: https://news.1rj.ru/str/sqlspecialist/523
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I saw a lot of big influencers copy pasting my content after removing the credits. It's absolutely fine for me as more people are getting free education because of my content.
But I will really appreciate if you share credits for the time and efforts I put in to create such valuable content. I hope you can understand.
Complete Python Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/548
Complete Excel Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/547
I'll have also posted learning series on Python, Power BI, Excel & Tableau.
Thanks to all who support our channel and share the content with proper credits. You guys are really amazing.
Hope it helps :)
Here are the links to the SQL series
Complete SQL Topics for Data Analyst: https://news.1rj.ru/str/sqlspecialist/523
Part-1: https://news.1rj.ru/str/sqlspecialist/524
Part-2: https://news.1rj.ru/str/sqlspecialist/525
Part-3: https://news.1rj.ru/str/sqlspecialist/526
Part-4: https://news.1rj.ru/str/sqlspecialist/527
Part-5: https://news.1rj.ru/str/sqlspecialist/529
Part-6: https://news.1rj.ru/str/sqlspecialist/534
Part-7: https://news.1rj.ru/str/sqlspecialist/534
Part-8: https://news.1rj.ru/str/sqlspecialist/536
Part-9: https://news.1rj.ru/str/sqlspecialist/537
Part-10: https://news.1rj.ru/str/sqlspecialist/539
Part-11: https://news.1rj.ru/str/sqlspecialist/540
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Part-17: https://news.1rj.ru/str/sqlspecialist/549
Part-18: https://news.1rj.ru/str/sqlspecialist/552
Part-19: https://news.1rj.ru/str/sqlspecialist/555
Part-20: https://news.1rj.ru/str/sqlspecialist/556
I saw a lot of big influencers copy pasting my content after removing the credits. It's absolutely fine for me as more people are getting free education because of my content.
But I will really appreciate if you share credits for the time and efforts I put in to create such valuable content. I hope you can understand.
Complete Python Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/548
Complete Excel Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/547
I'll have also posted learning series on Python, Power BI, Excel & Tableau.
Thanks to all who support our channel and share the content with proper credits. You guys are really amazing.
Hope it helps :)
👍22❤15👏2🥰1
Top 10 SQL interview questions with solutions by @sqlspecialist
1. What is the difference between WHERE and HAVING?
Solution:
WHERE filters rows before aggregation.
HAVING filters rows after aggregation.
2. Write a query to find the second-highest salary.
Solution:
3. How do you fetch the first 5 rows of a table?
Solution:
For SQL Server:
4. Write a query to find duplicate records in a table.
Solution:
5. How do you find employees who don’t belong to any department?
Solution:
6. What is a JOIN, and write a query to fetch data using INNER JOIN.
Solution:
A JOIN combines rows from two or more tables based on a related column.
7. Write a query to find the total number of employees in each department.
Solution:
8. How do you fetch the current date in SQL?
Solution:
9. Write a query to delete duplicate rows but keep one.
Solution:
10. What is a Common Table Expression (CTE), and how do you use it?
Solution:
A CTE is a temporary result set defined within a query.
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Hope it helps :)
#sql #dataanalysts
1. What is the difference between WHERE and HAVING?
Solution:
WHERE filters rows before aggregation.
HAVING filters rows after aggregation.
SELECT department, AVG(salary)
FROM employees
WHERE salary > 3000
GROUP BY department
HAVING AVG(salary) > 5000;
2. Write a query to find the second-highest salary.
Solution:
SELECT MAX(salary) AS second_highest_salary
FROM employees
WHERE salary < (SELECT MAX(salary) FROM employees);
3. How do you fetch the first 5 rows of a table?
Solution:
SELECT * FROM employees
LIMIT 5; -- (MySQL/PostgreSQL)
For SQL Server:
SELECT TOP 5 * FROM employees;
4. Write a query to find duplicate records in a table.
Solution:
SELECT column1, column2, COUNT(*)
FROM table_name
GROUP BY column1, column2
HAVING COUNT(*) > 1;
5. How do you find employees who don’t belong to any department?
Solution:
SELECT *
FROM employees
WHERE department_id IS NULL;
6. What is a JOIN, and write a query to fetch data using INNER JOIN.
Solution:
A JOIN combines rows from two or more tables based on a related column.
SELECT e.name, d.department_name
FROM employees e
INNER JOIN departments d ON e.department_id = d.id;
7. Write a query to find the total number of employees in each department.
Solution:
SELECT department_id, COUNT(*) AS total_employees
FROM employees
GROUP BY department_id;
8. How do you fetch the current date in SQL?
Solution:
SELECT CURRENT_DATE; -- MySQL/PostgreSQL
SELECT GETDATE(); -- SQL Server
9. Write a query to delete duplicate rows but keep one.
Solution:
WITH CTE AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY id) AS rn
FROM table_name
)
DELETE FROM CTE WHERE rn > 1;
10. What is a Common Table Expression (CTE), and how do you use it?
Solution:
A CTE is a temporary result set defined within a query.
WITH EmployeeCTE AS (
SELECT department_id, COUNT(*) AS total_employees
FROM employees
GROUP BY department_id
)
SELECT * FROM EmployeeCTE WHERE total_employees > 10;
I've curated essential SQL Interview Resources👇
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COMMON TABLEAU TERMINOLOGIES - PART 2
Today, let’s dive deeper into advanced Tableau terminologies that are essential for mastering data visualization and analytics.
Live Connection
A method of connecting Tableau directly to your data source, allowing real-time updates as the data changes.
Extract
A snapshot of your data stored locally as a Tableau Data Extract (TDE or Hyper file), enabling faster performance and offline analysis.
LOD Expressions (Level of Detail)
Advanced calculations in Tableau that allow you to control the level of granularity in your analysis.
Example: { FIXED [Region] : SUM([Sales]) } calculates total sales for each region, regardless of filters.
Blended Axis
Combining two measures on the same axis to show multiple data series in one chart.
Dual Axis
Creating two independent axes in the same visualization, often used for comparing different measures.
Discrete vs. Continuous
Discrete (Blue Pill): Represents individual, separate categories (e.g., Regions, Products).
Continuous (Green Pill): Represents numerical or time data, forming a continuous range (e.g., Sales, Dates).
Action
Interactive elements in Tableau that allow users to drill down, filter, or navigate between dashboards and sheets.
Groups
Custom categories created by combining multiple values in a dimension (e.g., grouping "Phones" and "Tablets" as "Mobile Devices").
Sets
Custom fields that define a subset of your data based on specific conditions. Sets are dynamic and can change based on your data.
Bins
Ranges of values used to group continuous data into discrete intervals (e.g., Sales ranges: 0-100, 101-200).
Trend Lines
A line added to a visualization to indicate the general direction or pattern in the data over time.
Forecasting
A Tableau feature that predicts future data trends based on historical patterns using statistical models.
Clustering
A feature in Tableau that groups similar data points together based on shared characteristics.
Data Pane
The left-hand panel in Tableau where dimensions, measures, and calculated fields are listed.
Analytics Pane
A panel in Tableau that provides drag-and-drop options for adding reference lines, trend lines, and forecasts.
Table Calculations
Calculations applied to the data within the context of the table or visualization.
Example: Calculating running totals, percentages of the total, or moving averages.
Join Types
Tableau supports various join types to combine tables from the same data source:
Inner Join: Only matching rows from both tables.
Left Join: All rows from the left table and matching rows from the right.
Right Join: All rows from the right table and matching rows from the left.
Full Outer Join: All rows from both tables, with NULLs for unmatched rows.
Union
Combining data from multiple tables by stacking rows (must have the same structure).
Hierarchies
Organizing dimensions into a tree-like structure to allow users to drill down or roll up data.
Performance Recording
A feature in Tableau to analyze the performance of your workbook, identifying slow queries or complex calculations.
Context Filters
Filters that create a dependent relationship between other filters, ensuring accurate and prioritized filtering.
Parameters
Dynamic input values that allow users to interact with the dashboard and change the output of calculations or visualizations.
Hyper File
A high-performance data engine format used by Tableau for faster extracts and real-time analytics.
Web Authoring
Creating or editing Tableau reports directly in a web browser without using Tableau Desktop.
Data Server
A Tableau Server component that stores shared data extracts and connections for collaboration.
Published Data Source
A data source uploaded to Tableau Server or Tableau Online for reuse and collaboration.
Resources to learn Tableau
Tableau Terminologies Part-1
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
Today, let’s dive deeper into advanced Tableau terminologies that are essential for mastering data visualization and analytics.
Live Connection
A method of connecting Tableau directly to your data source, allowing real-time updates as the data changes.
Extract
A snapshot of your data stored locally as a Tableau Data Extract (TDE or Hyper file), enabling faster performance and offline analysis.
LOD Expressions (Level of Detail)
Advanced calculations in Tableau that allow you to control the level of granularity in your analysis.
Example: { FIXED [Region] : SUM([Sales]) } calculates total sales for each region, regardless of filters.
Blended Axis
Combining two measures on the same axis to show multiple data series in one chart.
Dual Axis
Creating two independent axes in the same visualization, often used for comparing different measures.
Discrete vs. Continuous
Discrete (Blue Pill): Represents individual, separate categories (e.g., Regions, Products).
Continuous (Green Pill): Represents numerical or time data, forming a continuous range (e.g., Sales, Dates).
Action
Interactive elements in Tableau that allow users to drill down, filter, or navigate between dashboards and sheets.
Groups
Custom categories created by combining multiple values in a dimension (e.g., grouping "Phones" and "Tablets" as "Mobile Devices").
Sets
Custom fields that define a subset of your data based on specific conditions. Sets are dynamic and can change based on your data.
Bins
Ranges of values used to group continuous data into discrete intervals (e.g., Sales ranges: 0-100, 101-200).
Trend Lines
A line added to a visualization to indicate the general direction or pattern in the data over time.
Forecasting
A Tableau feature that predicts future data trends based on historical patterns using statistical models.
Clustering
A feature in Tableau that groups similar data points together based on shared characteristics.
Data Pane
The left-hand panel in Tableau where dimensions, measures, and calculated fields are listed.
Analytics Pane
A panel in Tableau that provides drag-and-drop options for adding reference lines, trend lines, and forecasts.
Table Calculations
Calculations applied to the data within the context of the table or visualization.
Example: Calculating running totals, percentages of the total, or moving averages.
Join Types
Tableau supports various join types to combine tables from the same data source:
Inner Join: Only matching rows from both tables.
Left Join: All rows from the left table and matching rows from the right.
Right Join: All rows from the right table and matching rows from the left.
Full Outer Join: All rows from both tables, with NULLs for unmatched rows.
Union
Combining data from multiple tables by stacking rows (must have the same structure).
Hierarchies
Organizing dimensions into a tree-like structure to allow users to drill down or roll up data.
Performance Recording
A feature in Tableau to analyze the performance of your workbook, identifying slow queries or complex calculations.
Context Filters
Filters that create a dependent relationship between other filters, ensuring accurate and prioritized filtering.
Parameters
Dynamic input values that allow users to interact with the dashboard and change the output of calculations or visualizations.
Hyper File
A high-performance data engine format used by Tableau for faster extracts and real-time analytics.
Web Authoring
Creating or editing Tableau reports directly in a web browser without using Tableau Desktop.
Data Server
A Tableau Server component that stores shared data extracts and connections for collaboration.
Published Data Source
A data source uploaded to Tableau Server or Tableau Online for reuse and collaboration.
Resources to learn Tableau
Tableau Terminologies Part-1
Share with credits: https://news.1rj.ru/str/sqlspecialist
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Top 10 Power BI interview questions with answers:
1. What are the key components of Power BI?
Solution:
Power Query: Data transformation and preparation.
Power Pivot: Data modeling.
Power View: Data visualization.
Power BI Service: Cloud-based sharing and collaboration.
Power BI Mobile: Mobile reports and dashboards.
2. What is DAX in Power BI?
Solution:
DAX (Data Analysis Expressions) is a formula language used in Power BI to create calculated columns, measures, and tables.
Example:
TotalSales = SUM(Sales[Amount])
3. What is the difference between a calculated column and a measure?
Solution:
Calculated Column: Computed row by row in the data model.
Measure: Computed at the aggregate level based on filters in a visualization.
4. How do you connect Power BI to a database?
Solution:
1. Open Power BI Desktop.
2. Go to Home > Get Data > Database (e.g., SQL Server).
3. Enter server and database details, then load or transform data.
5. What is the role of relationships in Power BI?
Solution:
Relationships define how tables in a data model are connected. Power BI uses relationships to filter and calculate data across multiple tables.
6. What are slicers in Power BI?
Solution:
Slicers are visual filters that allow users to interactively filter data in reports.
Example: A slicer for "Region" lets users view data specific to a selected region.
7. How do you implement Row-Level Security (RLS) in Power BI?
Solution:
1. Define roles in Modeling > Manage Roles.
2. Use DAX expressions to restrict data (e.g., [Region] = "North").
3. Assign roles to users in the Power BI Service.
8. What are the different types of joins in Power BI?
Solution:
Power BI offers the following join types in Power Query:
Inner Join
Left Outer Join
Right Outer Join
Full Outer Join
Anti Join (Left/Right Exclusion)
9. What is the difference between Power BI Pro and Power BI Premium?
Solution:
Power BI Pro: Allows sharing and collaboration for individual users.
Power BI Premium: Provides dedicated resources, larger dataset sizes, and supports enterprise-level usage.
10. How can you optimize Power BI reports for performance?
Solution:
- Use summarized datasets.
- Reduce visuals on a single page.
- Optimize DAX expressions.
- Enable aggregations for large datasets.
- Use query folding in Power Query.
I have curated essential Power BI Interview Resources👇
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1. What are the key components of Power BI?
Solution:
Power Query: Data transformation and preparation.
Power Pivot: Data modeling.
Power View: Data visualization.
Power BI Service: Cloud-based sharing and collaboration.
Power BI Mobile: Mobile reports and dashboards.
2. What is DAX in Power BI?
Solution:
DAX (Data Analysis Expressions) is a formula language used in Power BI to create calculated columns, measures, and tables.
Example:
TotalSales = SUM(Sales[Amount])
3. What is the difference between a calculated column and a measure?
Solution:
Calculated Column: Computed row by row in the data model.
Measure: Computed at the aggregate level based on filters in a visualization.
4. How do you connect Power BI to a database?
Solution:
1. Open Power BI Desktop.
2. Go to Home > Get Data > Database (e.g., SQL Server).
3. Enter server and database details, then load or transform data.
5. What is the role of relationships in Power BI?
Solution:
Relationships define how tables in a data model are connected. Power BI uses relationships to filter and calculate data across multiple tables.
6. What are slicers in Power BI?
Solution:
Slicers are visual filters that allow users to interactively filter data in reports.
Example: A slicer for "Region" lets users view data specific to a selected region.
7. How do you implement Row-Level Security (RLS) in Power BI?
Solution:
1. Define roles in Modeling > Manage Roles.
2. Use DAX expressions to restrict data (e.g., [Region] = "North").
3. Assign roles to users in the Power BI Service.
8. What are the different types of joins in Power BI?
Solution:
Power BI offers the following join types in Power Query:
Inner Join
Left Outer Join
Right Outer Join
Full Outer Join
Anti Join (Left/Right Exclusion)
9. What is the difference between Power BI Pro and Power BI Premium?
Solution:
Power BI Pro: Allows sharing and collaboration for individual users.
Power BI Premium: Provides dedicated resources, larger dataset sizes, and supports enterprise-level usage.
10. How can you optimize Power BI reports for performance?
Solution:
- Use summarized datasets.
- Reduce visuals on a single page.
- Optimize DAX expressions.
- Enable aggregations for large datasets.
- Use query folding in Power Query.
I have curated essential Power BI Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Like this post if you need more Power BI Resources 👍❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
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Top 10 Excel interview questions with answers:
1. What are the different types of cell references in Excel?
Solution:
1. Relative Reference: Changes when copied (e.g., A1).
2. Absolute Reference: Remains constant when copied (e.g., $A$1).
3. Mixed Reference: Partly absolute and partly relative (e.g., $A1 or A$1).
2. How do you remove duplicates in Excel?
Solution:
1. Select the data range.
2. Go to Data > Remove Duplicates.
3. Choose the columns to check for duplicates and click OK.
3. What is the difference between COUNT, COUNTA, and COUNTIF?
Solution:
COUNT: Counts numeric values.
COUNTA: Counts all non-empty cells (numbers, text, etc.).
COUNTIF: Counts cells based on a condition.
Example:
=COUNT(A1:A10) // Count numbers
=COUNTA(A1:A10) // Count all non-empty cells
=COUNTIF(A1:A10, ">50") // Count numbers > 50
4. What are pivot tables, and why are they used?
Solution:
Pivot tables summarize and analyze large datasets, allowing dynamic filtering and aggregation (e.g., sum, average, count) without altering the original data.
5. How do you protect a worksheet in Excel?
Solution:
1. Go to Review > Protect Sheet.
2. Set a password and select allowed actions (e.g., selecting cells).
3. Click OK to apply.
6. What is the difference between VLOOKUP and HLOOKUP?
Solution:
VLOOKUP: Searches for a value vertically in the leftmost column.
HLOOKUP: Searches for a value horizontally in the topmost row.
Example:
=VLOOKUP(101, A2:D10, 2, FALSE) // Find data for 101 vertically
=HLOOKUP("Jan", A1:Z2, 2, FALSE) // Find data for "Jan" horizontally.
7. What is conditional formatting in Excel?
Solution:
Conditional formatting highlights cells based on rules.
Steps:
1. Select cells.
2. Go to Home > Conditional Formatting.
3. Choose a rule (e.g., values greater than 50) and apply formatting.
8. How do you find duplicates using a formula in Excel?
Solution:
Use the COUNTIF function:
=IF(COUNTIF(A:A, A2) > 1, "Duplicate", "Unique")
9. How do you use the IF function?
Solution:
The IF function performs logical tests and returns a value based on the result.
=IF(A1 > 50, "Pass", "Fail") // Returns "Pass" if A1 > 50, else "Fail"
10. What is the purpose of the TEXT function?
Solution:
The TEXT function formats numbers and dates into specified text formats.
Example:
=TEXT(A1, "DD-MMM-YYYY") // Converts date to "22-Nov-2024"
=TEXT(1234.56, "$#,##0.00") // Formats number as "$1,234.56"
Like for more ❤️
I have curated best 80+ top-notch Data Analytics Resources 👇👇
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Hope this helps you 😊
1. What are the different types of cell references in Excel?
Solution:
1. Relative Reference: Changes when copied (e.g., A1).
2. Absolute Reference: Remains constant when copied (e.g., $A$1).
3. Mixed Reference: Partly absolute and partly relative (e.g., $A1 or A$1).
2. How do you remove duplicates in Excel?
Solution:
1. Select the data range.
2. Go to Data > Remove Duplicates.
3. Choose the columns to check for duplicates and click OK.
3. What is the difference between COUNT, COUNTA, and COUNTIF?
Solution:
COUNT: Counts numeric values.
COUNTA: Counts all non-empty cells (numbers, text, etc.).
COUNTIF: Counts cells based on a condition.
Example:
=COUNT(A1:A10) // Count numbers
=COUNTA(A1:A10) // Count all non-empty cells
=COUNTIF(A1:A10, ">50") // Count numbers > 50
4. What are pivot tables, and why are they used?
Solution:
Pivot tables summarize and analyze large datasets, allowing dynamic filtering and aggregation (e.g., sum, average, count) without altering the original data.
5. How do you protect a worksheet in Excel?
Solution:
1. Go to Review > Protect Sheet.
2. Set a password and select allowed actions (e.g., selecting cells).
3. Click OK to apply.
6. What is the difference between VLOOKUP and HLOOKUP?
Solution:
VLOOKUP: Searches for a value vertically in the leftmost column.
HLOOKUP: Searches for a value horizontally in the topmost row.
Example:
=VLOOKUP(101, A2:D10, 2, FALSE) // Find data for 101 vertically
=HLOOKUP("Jan", A1:Z2, 2, FALSE) // Find data for "Jan" horizontally.
7. What is conditional formatting in Excel?
Solution:
Conditional formatting highlights cells based on rules.
Steps:
1. Select cells.
2. Go to Home > Conditional Formatting.
3. Choose a rule (e.g., values greater than 50) and apply formatting.
8. How do you find duplicates using a formula in Excel?
Solution:
Use the COUNTIF function:
=IF(COUNTIF(A:A, A2) > 1, "Duplicate", "Unique")
9. How do you use the IF function?
Solution:
The IF function performs logical tests and returns a value based on the result.
=IF(A1 > 50, "Pass", "Fail") // Returns "Pass" if A1 > 50, else "Fail"
10. What is the purpose of the TEXT function?
Solution:
The TEXT function formats numbers and dates into specified text formats.
Example:
=TEXT(A1, "DD-MMM-YYYY") // Converts date to "22-Nov-2024"
=TEXT(1234.56, "$#,##0.00") // Formats number as "$1,234.56"
Like for more ❤️
I have curated best 80+ top-notch Data Analytics Resources 👇👇
https://news.1rj.ru/str/DataSimplifier
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Hi guys,
Since I got a lot of requests, so I've decided to teach SQL from scratch!
You can find more details here
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I'll also be asking questions along the way, so make sure to join our discussion group to participate
Hope it helps :)
Since I got a lot of requests, so I've decided to teach SQL from scratch!
You can find more details here
👇👇
https://news.1rj.ru/str/sqlanalyst/663
I'll also be asking questions along the way, so make sure to join our discussion group to participate
Hope it helps :)
👍12❤7👏2
Power BI Complete Roadmap: From Basics to Advanced
1. Introduction to Power BI
Understand Power BI Desktop, Service, and Mobile.
Install Power BI Desktop and familiarize with the interface.
2. Data Import & Transformation
Import data from various sources (Excel, SQL, Web).
Use Power Query for data cleaning and transformation.
3. Data Modeling
Create relationships between tables (one-to-many, many-to-one).
Build calculated columns and measures using DAX.
4. DAX Basics
Learn aggregation functions (SUM, AVERAGE, COUNT).
Use CALCULATE and Time Intelligence functions.
5. Visualizations
Create bar, line, pie charts, and tables.
Use slicers, filters, and drill-through for interactivity.
6. Power BI Service
Publish and share reports.
Create dashboards and set up row-level security.
7. Power BI Mobile
View and interact with reports on mobile devices.
Optimize reports for mobile view.
8. Advanced Power Query
Use custom functions and M Language.
Apply query folding and parameters for dynamic queries.
9. Power BI Integration
Integrate with Excel, Power Automate, and Power Apps.
Connect to Azure services for cloud-based analytics.
10. Publishing & Distribution
Set up scheduled data refresh and publish on Power BI Report Server.
Embed reports using Power BI Embedded.
11. Best Practices
Optimize performance and follow design principles for user-friendly reports.
Ensure data security and compliance.
I have curated essential Power BI Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Like this post if you need more Power BI Resources 👍❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
1. Introduction to Power BI
Understand Power BI Desktop, Service, and Mobile.
Install Power BI Desktop and familiarize with the interface.
2. Data Import & Transformation
Import data from various sources (Excel, SQL, Web).
Use Power Query for data cleaning and transformation.
3. Data Modeling
Create relationships between tables (one-to-many, many-to-one).
Build calculated columns and measures using DAX.
4. DAX Basics
Learn aggregation functions (SUM, AVERAGE, COUNT).
Use CALCULATE and Time Intelligence functions.
5. Visualizations
Create bar, line, pie charts, and tables.
Use slicers, filters, and drill-through for interactivity.
6. Power BI Service
Publish and share reports.
Create dashboards and set up row-level security.
7. Power BI Mobile
View and interact with reports on mobile devices.
Optimize reports for mobile view.
8. Advanced Power Query
Use custom functions and M Language.
Apply query folding and parameters for dynamic queries.
9. Power BI Integration
Integrate with Excel, Power Automate, and Power Apps.
Connect to Azure services for cloud-based analytics.
10. Publishing & Distribution
Set up scheduled data refresh and publish on Power BI Report Server.
Embed reports using Power BI Embedded.
11. Best Practices
Optimize performance and follow design principles for user-friendly reports.
Ensure data security and compliance.
I have curated essential Power BI Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Like this post if you need more Power BI Resources 👍❤️
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
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SQL Roadmap: From Basics to Advanced
1. Basics
Learn SQL syntax: SELECT, WHERE, ORDER BY.
Understand data types (INT, VARCHAR, DATE).
Use operators (=, <>, >, <), logical operators (AND, OR, NOT), and comparison operators.
2. Filtering & Sorting
Filter data with WHERE clause.
Sort results using ORDER BY.
Use wildcards (LIKE, %).
3. Aggregations
Apply aggregation functions: COUNT, SUM, AVG, MAX, MIN.
Group data with GROUP BY, filter groups with HAVING.
4. Joins
Learn different joins: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN.
Understand when to use each join type.
5. Subqueries
Use subqueries in SELECT, WHERE, FROM clauses.
Differentiate between correlated and non-correlated subqueries.
6. Set Operations
Use UNION, INTERSECT, and EXCEPT to combine results.
7. Data Modification
Insert data with INSERT INTO.
Update data using UPDATE.
Delete data with DELETE.
8. Advanced Queries
Use CASE for conditional logic.
Learn window functions: ROW_NUMBER, RANK, DENSE_RANK.
Use CTEs (Common Table Expressions) for modular queries.
9. Indexes & Performance
Create and use indexes.
Optimize queries by avoiding SELECT *
10. Transactions
Use COMMIT, ROLLBACK, and SAVEPOINT.
Understand ACID properties.
11. Stored Procedures & Functions
Create and execute stored procedures.
Define and use functions for reusable logic.
12. Database Design
Learn normalization (1NF, 2NF, 3NF).
Understand primary/foreign keys and relationships.
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
1. Basics
Learn SQL syntax: SELECT, WHERE, ORDER BY.
Understand data types (INT, VARCHAR, DATE).
Use operators (=, <>, >, <), logical operators (AND, OR, NOT), and comparison operators.
2. Filtering & Sorting
Filter data with WHERE clause.
Sort results using ORDER BY.
Use wildcards (LIKE, %).
3. Aggregations
Apply aggregation functions: COUNT, SUM, AVG, MAX, MIN.
Group data with GROUP BY, filter groups with HAVING.
4. Joins
Learn different joins: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN.
Understand when to use each join type.
5. Subqueries
Use subqueries in SELECT, WHERE, FROM clauses.
Differentiate between correlated and non-correlated subqueries.
6. Set Operations
Use UNION, INTERSECT, and EXCEPT to combine results.
7. Data Modification
Insert data with INSERT INTO.
Update data using UPDATE.
Delete data with DELETE.
8. Advanced Queries
Use CASE for conditional logic.
Learn window functions: ROW_NUMBER, RANK, DENSE_RANK.
Use CTEs (Common Table Expressions) for modular queries.
9. Indexes & Performance
Create and use indexes.
Optimize queries by avoiding SELECT *
10. Transactions
Use COMMIT, ROLLBACK, and SAVEPOINT.
Understand ACID properties.
11. Stored Procedures & Functions
Create and execute stored procedures.
Define and use functions for reusable logic.
12. Database Design
Learn normalization (1NF, 2NF, 3NF).
Understand primary/foreign keys and relationships.
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
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Top 10 Python interview questions with answers:
1. What are Python's key data types?
Solution:
Numeric types: int, float, complex
Text type: str
Sequence types: list, tuple
Mapping type: dict
Set types: set, frozenset
Boolean type: bool
2. What is a list comprehension in Python?
Solution:
A concise way to create lists using a single line of code.
Example:
squares = [x**2 for x in range(10)] # [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
3. What is the difference between == and is in Python?
Solution:
== checks for value equality.
is checks for object identity (whether two references point to the same object).
a = [1, 2, 3]
b = [1, 2, 3]
print(a == b) # True, values are equal
print(a is b) # False, different objects
4. How do you handle exceptions in Python?
Solution:
Using try, except, else, and finally blocks.
Example:
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero!")
else:
print("No error occurred.")
finally:
print("This block runs regardless of an error.")
5. What are Python decorators and why are they used?
Solution:
Decorators are functions that modify the behavior of other functions or methods. They are used for adding functionality without changing the original function's code. Example:
def my_decorator(func):
def wrapper():
print("Something is happening before the function is called.")
func()
print("Something is happening after the function is called.")
return wrapper
def say_hello():
print("Hello!")
say_hello()
6. What is a Python generator?
Solution:
A generator is a function that uses yield to return an iterator, which generates values on the fly without storing them in memory. Example:
def my_generator():
yield 1
yield 2
yield 3
gen = my_generator()
for value in gen:
print(value)
7. How do you create a dictionary in Python?
Solution:
my_dict = {'name': 'John', 'age': 30, 'city': 'New York'}
8. What is the difference between append() and extend() in Python?
Solution:
append(): Adds a single element to the end of a list.
extend(): Adds all elements from an iterable to the end of a list.
my_list = [1, 2, 3]
my_list.append([4, 5]) # [1, 2, 3, [4, 5]]
my_list.extend([6, 7]) # [1, 2, 3, [4, 5], 6, 7]
9. What is a lambda function in Python?
Solution:
A lambda function is an anonymous function defined using the lambda keyword. It's often used for short, simple operations. Example:
square = lambda x: x**2
print(square(5)) # 25
10. What is the Global Interpreter Lock (GIL)?
Solution:
The GIL is a mutex in CPython (the standard Python implementation) that prevents multiple native threads from executing Python bytecode at the same time. This can limit the performance of multithreaded Python programs in CPU-bound operations but not in I/O-bound operations.
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1. What are Python's key data types?
Solution:
Numeric types: int, float, complex
Text type: str
Sequence types: list, tuple
Mapping type: dict
Set types: set, frozenset
Boolean type: bool
2. What is a list comprehension in Python?
Solution:
A concise way to create lists using a single line of code.
Example:
squares = [x**2 for x in range(10)] # [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
3. What is the difference between == and is in Python?
Solution:
== checks for value equality.
is checks for object identity (whether two references point to the same object).
a = [1, 2, 3]
b = [1, 2, 3]
print(a == b) # True, values are equal
print(a is b) # False, different objects
4. How do you handle exceptions in Python?
Solution:
Using try, except, else, and finally blocks.
Example:
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero!")
else:
print("No error occurred.")
finally:
print("This block runs regardless of an error.")
5. What are Python decorators and why are they used?
Solution:
Decorators are functions that modify the behavior of other functions or methods. They are used for adding functionality without changing the original function's code. Example:
def my_decorator(func):
def wrapper():
print("Something is happening before the function is called.")
func()
print("Something is happening after the function is called.")
return wrapper
@my_decoratordef say_hello():
print("Hello!")
say_hello()
6. What is a Python generator?
Solution:
A generator is a function that uses yield to return an iterator, which generates values on the fly without storing them in memory. Example:
def my_generator():
yield 1
yield 2
yield 3
gen = my_generator()
for value in gen:
print(value)
7. How do you create a dictionary in Python?
Solution:
my_dict = {'name': 'John', 'age': 30, 'city': 'New York'}
8. What is the difference between append() and extend() in Python?
Solution:
append(): Adds a single element to the end of a list.
extend(): Adds all elements from an iterable to the end of a list.
my_list = [1, 2, 3]
my_list.append([4, 5]) # [1, 2, 3, [4, 5]]
my_list.extend([6, 7]) # [1, 2, 3, [4, 5], 6, 7]
9. What is a lambda function in Python?
Solution:
A lambda function is an anonymous function defined using the lambda keyword. It's often used for short, simple operations. Example:
square = lambda x: x**2
print(square(5)) # 25
10. What is the Global Interpreter Lock (GIL)?
Solution:
The GIL is a mutex in CPython (the standard Python implementation) that prevents multiple native threads from executing Python bytecode at the same time. This can limit the performance of multithreaded Python programs in CPU-bound operations but not in I/O-bound operations.
Here you can find essential Python Interview Resources👇
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SQL isn't easy!
It’s the powerful language that helps you manage and manipulate data in databases.
To truly master SQL, focus on these key areas:
0. Understanding the Basics: Get comfortable with SQL syntax, data types, and basic queries like SELECT, INSERT, UPDATE, and DELETE.
1. Mastering Data Retrieval: Learn advanced SELECT statements, including JOINs, GROUP BY, HAVING, and subqueries to retrieve complex datasets.
2. Working with Aggregation Functions: Use functions like COUNT(), SUM(), AVG(), MIN(), and MAX() to summarize and analyze data efficiently.
3. Optimizing Queries: Understand how to write efficient queries and use techniques like indexing and query execution plans for performance optimization.
4. Creating and Managing Databases: Master CREATE, ALTER, and DROP commands for building and maintaining database structures.
5. Understanding Constraints and Keys: Learn the importance of primary keys, foreign keys, unique constraints, and indexes for data integrity.
6. Advanced SQL Techniques: Dive into CASE statements, CTEs (Common Table Expressions), window functions, and stored procedures for more powerful querying.
7. Normalizing Data: Understand database normalization principles and how to design databases to avoid redundancy and ensure consistency.
8. Handling Transactions: Learn how to use BEGIN, COMMIT, and ROLLBACK to manage transactions and ensure data integrity.
9. Staying Updated with SQL Trends: The world of databases evolves—stay informed about new SQL functions, database management systems (DBMS), and best practices.
⏳ With practice, hands-on experience, and a thirst for learning, SQL will empower you to unlock the full potential of data!
You can read detailed article here
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
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It’s the powerful language that helps you manage and manipulate data in databases.
To truly master SQL, focus on these key areas:
0. Understanding the Basics: Get comfortable with SQL syntax, data types, and basic queries like SELECT, INSERT, UPDATE, and DELETE.
1. Mastering Data Retrieval: Learn advanced SELECT statements, including JOINs, GROUP BY, HAVING, and subqueries to retrieve complex datasets.
2. Working with Aggregation Functions: Use functions like COUNT(), SUM(), AVG(), MIN(), and MAX() to summarize and analyze data efficiently.
3. Optimizing Queries: Understand how to write efficient queries and use techniques like indexing and query execution plans for performance optimization.
4. Creating and Managing Databases: Master CREATE, ALTER, and DROP commands for building and maintaining database structures.
5. Understanding Constraints and Keys: Learn the importance of primary keys, foreign keys, unique constraints, and indexes for data integrity.
6. Advanced SQL Techniques: Dive into CASE statements, CTEs (Common Table Expressions), window functions, and stored procedures for more powerful querying.
7. Normalizing Data: Understand database normalization principles and how to design databases to avoid redundancy and ensure consistency.
8. Handling Transactions: Learn how to use BEGIN, COMMIT, and ROLLBACK to manage transactions and ensure data integrity.
9. Staying Updated with SQL Trends: The world of databases evolves—stay informed about new SQL functions, database management systems (DBMS), and best practices.
⏳ With practice, hands-on experience, and a thirst for learning, SQL will empower you to unlock the full potential of data!
You can read detailed article here
I've curated essential SQL Interview Resources👇
https://news.1rj.ru/str/DataSimplifier
Share with credits: https://news.1rj.ru/str/sqlspecialist
Hope it helps :)
👍24❤5👏2
Many people pay too much to learn SQL, but my mission is to break down barriers. I have shared complete learning series to learn SQL from scratch.
Here are the links to the SQL series
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I saw a lot of big influencers copy pasting my content after removing the credits. It's absolutely fine for me as more people are getting free education because of my content.
But I will really appreciate if you share credits for the time and efforts I put in to create such valuable content. I hope you can understand.
Complete Python Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/548
Complete Excel Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/547
I have also shared learning series on Python, Power BI & Excel.
Thanks to all who support our channel and share the content with proper credits. You guys are really amazing.
Hope it helps :)
Here are the links to the SQL series
Complete SQL Topics for Data Analyst: https://news.1rj.ru/str/sqlspecialist/523
Part-1: https://news.1rj.ru/str/sqlspecialist/524
Part-2: https://news.1rj.ru/str/sqlspecialist/525
Part-3: https://news.1rj.ru/str/sqlspecialist/526
Part-4: https://news.1rj.ru/str/sqlspecialist/527
Part-5: https://news.1rj.ru/str/sqlspecialist/529
Part-6: https://news.1rj.ru/str/sqlspecialist/534
Part-7: https://news.1rj.ru/str/sqlspecialist/534
Part-8: https://news.1rj.ru/str/sqlspecialist/536
Part-9: https://news.1rj.ru/str/sqlspecialist/537
Part-10: https://news.1rj.ru/str/sqlspecialist/539
Part-11: https://news.1rj.ru/str/sqlspecialist/540
Part-12:
https://news.1rj.ru/str/sqlspecialist/541
Part-13: https://news.1rj.ru/str/sqlspecialist/542
Part-14: https://news.1rj.ru/str/sqlspecialist/544
Part-15: https://news.1rj.ru/str/sqlspecialist/545
Part-16: https://news.1rj.ru/str/sqlspecialist/546
Part-17: https://news.1rj.ru/str/sqlspecialist/549
Part-18: https://news.1rj.ru/str/sqlspecialist/552
Part-19: https://news.1rj.ru/str/sqlspecialist/555
Part-20: https://news.1rj.ru/str/sqlspecialist/556
I saw a lot of big influencers copy pasting my content after removing the credits. It's absolutely fine for me as more people are getting free education because of my content.
But I will really appreciate if you share credits for the time and efforts I put in to create such valuable content. I hope you can understand.
Complete Python Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/548
Complete Excel Topics for Data Analysts: https://news.1rj.ru/str/sqlspecialist/547
I have also shared learning series on Python, Power BI & Excel.
Thanks to all who support our channel and share the content with proper credits. You guys are really amazing.
Hope it helps :)
👍31❤27🔥6
Top 10 Tableau concepts for interviews:
1. Data Connections: Import data from multiple sources like Excel, SQL, and cloud services.
2. Dimensions and Measures: Dimensions categorize data, while measures provide numeric calculations.
3. Filters: Apply data filters at the worksheet, dashboard, or data source level.
4. Calculated Fields: Create custom calculations for advanced analysis.
5. Tableau Joins and Blending: Combine data from multiple sources; joins occur within a source, while blending connects separate sources.
6. Charts and Visualizations: Master bar charts, line charts, scatter plots, heat maps, and dashboards.
7. Table Calculations: Perform operations like running total, percentage difference, and moving average.
8. LOD Expressions: Fixed, Include, and Exclude expressions for granular data control.
9. Dashboards: Combine multiple worksheets into interactive dashboards with filters and actions.
10. Publishing and Sharing: Share insights via Tableau Server, Tableau Online, or Tableau Public.
Best Resources to learn Tableau
Data Analyst Checklist
Like this post if you want me to continue this Tableau series 👍♥️
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1. Data Connections: Import data from multiple sources like Excel, SQL, and cloud services.
2. Dimensions and Measures: Dimensions categorize data, while measures provide numeric calculations.
3. Filters: Apply data filters at the worksheet, dashboard, or data source level.
4. Calculated Fields: Create custom calculations for advanced analysis.
5. Tableau Joins and Blending: Combine data from multiple sources; joins occur within a source, while blending connects separate sources.
6. Charts and Visualizations: Master bar charts, line charts, scatter plots, heat maps, and dashboards.
7. Table Calculations: Perform operations like running total, percentage difference, and moving average.
8. LOD Expressions: Fixed, Include, and Exclude expressions for granular data control.
9. Dashboards: Combine multiple worksheets into interactive dashboards with filters and actions.
10. Publishing and Sharing: Share insights via Tableau Server, Tableau Online, or Tableau Public.
Best Resources to learn Tableau
Data Analyst Checklist
Like this post if you want me to continue this Tableau series 👍♥️
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Top 10 concepts for Data Analyst interviews 👇👇
1. Data Cleaning: Techniques to handle missing, duplicate, and inconsistent data.
2. SQL: Strong knowledge of Joins, Group By, Window Functions, and Subqueries.
3. Excel: Proficiency in Pivot Tables, VLOOKUP, Conditional Formatting, and advanced formulas.
4. Visualization Tools: Expertise in Tableau, Power BI, or similar tools for dashboards and insights.
5. Data Wrangling: Extracting, transforming, and loading (ETL) data from various sources.
6. Statistics: Basic understanding of mean, median, standard deviation, correlation, and hypothesis testing.
7. Python/R: Ability to use libraries like Pandas, NumPy, and Matplotlib for analysis.
8. Business Acumen: Translate data insights into actionable recommendations for stakeholders.
9. Data Modeling: Create relationships between datasets and understand star/snowflake schema.
10. A/B Testing: Design and interpret experiments to compare group performance.
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1. Data Cleaning: Techniques to handle missing, duplicate, and inconsistent data.
2. SQL: Strong knowledge of Joins, Group By, Window Functions, and Subqueries.
3. Excel: Proficiency in Pivot Tables, VLOOKUP, Conditional Formatting, and advanced formulas.
4. Visualization Tools: Expertise in Tableau, Power BI, or similar tools for dashboards and insights.
5. Data Wrangling: Extracting, transforming, and loading (ETL) data from various sources.
6. Statistics: Basic understanding of mean, median, standard deviation, correlation, and hypothesis testing.
7. Python/R: Ability to use libraries like Pandas, NumPy, and Matplotlib for analysis.
8. Business Acumen: Translate data insights into actionable recommendations for stakeholders.
9. Data Modeling: Create relationships between datasets and understand star/snowflake schema.
10. A/B Testing: Design and interpret experiments to compare group performance.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
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👍19❤11👏2🎉1
Top 15 Excel concepts for Interviews
1. Cell Referencing: Understand absolute ($A$1), relative (A1), and mixed ($A1, A$1) referencing for dynamic formulas.
2. Formulas and Functions: Master key functions like VLOOKUP, HLOOKUP, IF, INDEX, MATCH, TEXT, CONCATENATE, and XLOOKUP.
3. Pivot Tables: Summarize, analyze, and visualize data dynamically; learn grouping and calculated fields.
4. Conditional Formatting: Highlight cells based on specific criteria using colors, icons, or data bars.
5. Data Validation: Restrict inputs using rules like drop-down lists, numerical ranges, or text length.
6. Charts: Create visualizations such as bar charts, pie charts, scatter plots, line graphs, and combo charts.
7. Filters and Sorting: Organize data using filters and multi-level sorting by color, values, or custom lists.
8. Macros: Automate repetitive tasks using VBA or Excel’s macro recorder.
9. What-If Analysis: Use tools like Goal Seek, Scenario Manager, and Data Tables for forecasting.
10. Power Query: Import, clean, and transform data from various sources with ease.
11. Error Handling: Understand and resolve common errors like #DIV/0!, #N/A, #VALUE!, #REF!, and use IFERROR.
12. Dynamic Arrays: Work with functions like SORT, FILTER, SEQUENCE, and UNIQUE for scalable solutions.
13. Advanced Charts: Use sparklines, waterfall charts, heat maps, and histogram charts for advanced visualization.
14. Data Cleaning: Remove duplicates, trim excess spaces, clean inconsistent formatting, and split data with TEXT TO COLUMNS.
15. Workbook/Worksheet Protection: Protect cells, worksheets, or entire workbooks to prevent unintended changes.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
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1. Cell Referencing: Understand absolute ($A$1), relative (A1), and mixed ($A1, A$1) referencing for dynamic formulas.
2. Formulas and Functions: Master key functions like VLOOKUP, HLOOKUP, IF, INDEX, MATCH, TEXT, CONCATENATE, and XLOOKUP.
3. Pivot Tables: Summarize, analyze, and visualize data dynamically; learn grouping and calculated fields.
4. Conditional Formatting: Highlight cells based on specific criteria using colors, icons, or data bars.
5. Data Validation: Restrict inputs using rules like drop-down lists, numerical ranges, or text length.
6. Charts: Create visualizations such as bar charts, pie charts, scatter plots, line graphs, and combo charts.
7. Filters and Sorting: Organize data using filters and multi-level sorting by color, values, or custom lists.
8. Macros: Automate repetitive tasks using VBA or Excel’s macro recorder.
9. What-If Analysis: Use tools like Goal Seek, Scenario Manager, and Data Tables for forecasting.
10. Power Query: Import, clean, and transform data from various sources with ease.
11. Error Handling: Understand and resolve common errors like #DIV/0!, #N/A, #VALUE!, #REF!, and use IFERROR.
12. Dynamic Arrays: Work with functions like SORT, FILTER, SEQUENCE, and UNIQUE for scalable solutions.
13. Advanced Charts: Use sparklines, waterfall charts, heat maps, and histogram charts for advanced visualization.
14. Data Cleaning: Remove duplicates, trim excess spaces, clean inconsistent formatting, and split data with TEXT TO COLUMNS.
15. Workbook/Worksheet Protection: Protect cells, worksheets, or entire workbooks to prevent unintended changes.
I have curated best 80+ top-notch Data Analytics Resources 👇👇
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7 Baby Steps to Learn SQL
1. Understand the Basics: Start by learning the foundational concepts of SQL. Understand what SQL is, its role in managing databases, and basic operations like selecting data using SELECT, filtering with WHERE, and sorting with ORDER BY. Familiarize yourself with relational database management systems (RDBMS) such as MySQL, PostgreSQL, or SQLite.
2. Master CRUD Operations: Practice writing SQL queries to perform CRUD operations (Create, Read, Update, Delete). Learn how to:
Insert data using INSERT INTO.
Retrieve data with SELECT.
Update records with UPDATE.
Delete rows using DELETE.
3. Work with Functions and Aggregations: Dive into SQL functions and aggregate queries. Understand how to use functions like MIN, MAX, AVG, COUNT, and SUM. Practice grouping data with GROUP BY and filtering aggregated data using HAVING.
4. Explore Joins and Relationships: Learn to combine data from multiple tables using different types of joins (INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN). Understand table relationships (one-to-one, one-to-many, many-to-many) and how to leverage them effectively in queries.
5. Write Complex Queries: Advance to writing more complex SQL queries, including subqueries, Common Table Expressions (CTEs), and nested queries. Practice scenarios like finding duplicate entries, ranking data, or retrieving hierarchical data.
6. Understand Database Design: Learn about database normalization and denormalization to design efficient database schemas. Understand primary keys, foreign keys, constraints, and indexing to optimize query performance.
7. Engage with SQL Communities: Join SQL forums, GitHub repositories, and platforms like StackOverflow, or WhatsApp's SQL community. Participate in SQL challenges on websites like HackerRank, LeetCode, or Stratascrach to sharpen your skills and get feedback from experienced developers.
Additional Tips:
- Work on real-world datasets to understand practical applications.
- Explore advanced concepts like stored procedures, triggers, and views as you progress.
- Regularly review your queries to find optimization opportunities.
I've curated essential SQL Interview Resources👇
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
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1. Understand the Basics: Start by learning the foundational concepts of SQL. Understand what SQL is, its role in managing databases, and basic operations like selecting data using SELECT, filtering with WHERE, and sorting with ORDER BY. Familiarize yourself with relational database management systems (RDBMS) such as MySQL, PostgreSQL, or SQLite.
2. Master CRUD Operations: Practice writing SQL queries to perform CRUD operations (Create, Read, Update, Delete). Learn how to:
Insert data using INSERT INTO.
Retrieve data with SELECT.
Update records with UPDATE.
Delete rows using DELETE.
3. Work with Functions and Aggregations: Dive into SQL functions and aggregate queries. Understand how to use functions like MIN, MAX, AVG, COUNT, and SUM. Practice grouping data with GROUP BY and filtering aggregated data using HAVING.
4. Explore Joins and Relationships: Learn to combine data from multiple tables using different types of joins (INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN). Understand table relationships (one-to-one, one-to-many, many-to-many) and how to leverage them effectively in queries.
5. Write Complex Queries: Advance to writing more complex SQL queries, including subqueries, Common Table Expressions (CTEs), and nested queries. Practice scenarios like finding duplicate entries, ranking data, or retrieving hierarchical data.
6. Understand Database Design: Learn about database normalization and denormalization to design efficient database schemas. Understand primary keys, foreign keys, constraints, and indexing to optimize query performance.
7. Engage with SQL Communities: Join SQL forums, GitHub repositories, and platforms like StackOverflow, or WhatsApp's SQL community. Participate in SQL challenges on websites like HackerRank, LeetCode, or Stratascrach to sharpen your skills and get feedback from experienced developers.
Additional Tips:
- Work on real-world datasets to understand practical applications.
- Explore advanced concepts like stored procedures, triggers, and views as you progress.
- Regularly review your queries to find optimization opportunities.
I've curated essential SQL Interview Resources👇
https://whatsapp.com/channel/0029VaGgzAk72WTmQFERKh02
Share with credits: https://news.1rj.ru/str/sqlspecialist
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Anyone with an Internet connection can learn 𝗗𝗮𝘁𝗮 𝗔𝗻𝗮𝗹𝘆𝘀𝗶𝘀 𝗳𝗼𝗿 𝗳𝗿𝗲𝗲:
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No more excuses now.
SQL - https://lnkd.in/gQkjdAWP
Python - https://lnkd.in/gQk8siKn
Excel - https://lnkd.in/d-txjPJn
Power BI - https://lnkd.in/gs6RgH2m
Tableau - https://lnkd.in/dDFdyS8y
Data Visualization - https://lnkd.in/dcHqhgn4
Data Cleaning - https://lnkd.in/dCXspR4p
Google Sheets - https://lnkd.in/d7eDi8pn
Statistics - https://lnkd.in/dgaw6KMW
Projects - https://lnkd.in/g2Fjzbma
Portfolio - https://news.1rj.ru/str/DataPortfolio
If you've read so far, do LIKE and share this channel with your friends & loved ones ♥️
Hope it helps :)
❤47👍27🥰4👏3👎2
7 Baby Steps to Learn Excel
1. Understand the Basics: Start by getting familiar with Excel's interface, including workbooks, worksheets, cells, rows, and columns. Learn basic operations like entering and editing data, formatting cells, and using basic formulas (e.g., SUM, AVERAGE, COUNT).
2. Master Essential Functions: Excel's power lies in its functions. Focus on learning frequently used ones like:
Mathematical: SUM, AVERAGE, ROUND
Text: CONCATENATE, LEFT, RIGHT, LEN
Logical: IF, AND, OR
Lookup: VLOOKUP, HLOOKUP, INDEX, MATCH
3. Work with Data: Learn how to organize, sort, and filter data effectively. Practice creating and formatting tables to handle structured data, and explore data validation to restrict input values.
4. Visualize with Charts: Understand how to create charts like bar, line, and pie charts to represent data visually. Learn the importance of choosing the right chart type and practice customizing them for clarity and impact.
5. Explore Pivot Tables: Pivot tables are essential for summarizing large datasets. Learn how to create pivot tables, use slicers for dynamic filtering, and analyze data using fields like Rows, Columns, Values, and Filters.
6. Use Advanced Features: Dive into advanced features like conditional formatting, macros, and Excel's built-in tools for data analysis (e.g., Goal Seek, Solver, and Data Analysis ToolPak). Learn how to work with Array Formulas and explore the power of XLOOKUP (in newer versions).
7. Engage with Excel Communities: Join Excel communities on forums like Reddit’s r/Excel, or Microsoft’s Excel Community. Participate in challenges on platforms like ExcelJet, LeetCode, or Kaggle to improve your problem-solving skills and get insights from experts.
Additional Tips:
- Regularly practice on real-world datasets.
- Learn keyboard shortcuts to speed up your work.
- Explore Microsoft Excel's official documentation and free online tutorials for deeper insights.
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1. Understand the Basics: Start by getting familiar with Excel's interface, including workbooks, worksheets, cells, rows, and columns. Learn basic operations like entering and editing data, formatting cells, and using basic formulas (e.g., SUM, AVERAGE, COUNT).
2. Master Essential Functions: Excel's power lies in its functions. Focus on learning frequently used ones like:
Mathematical: SUM, AVERAGE, ROUND
Text: CONCATENATE, LEFT, RIGHT, LEN
Logical: IF, AND, OR
Lookup: VLOOKUP, HLOOKUP, INDEX, MATCH
3. Work with Data: Learn how to organize, sort, and filter data effectively. Practice creating and formatting tables to handle structured data, and explore data validation to restrict input values.
4. Visualize with Charts: Understand how to create charts like bar, line, and pie charts to represent data visually. Learn the importance of choosing the right chart type and practice customizing them for clarity and impact.
5. Explore Pivot Tables: Pivot tables are essential for summarizing large datasets. Learn how to create pivot tables, use slicers for dynamic filtering, and analyze data using fields like Rows, Columns, Values, and Filters.
6. Use Advanced Features: Dive into advanced features like conditional formatting, macros, and Excel's built-in tools for data analysis (e.g., Goal Seek, Solver, and Data Analysis ToolPak). Learn how to work with Array Formulas and explore the power of XLOOKUP (in newer versions).
7. Engage with Excel Communities: Join Excel communities on forums like Reddit’s r/Excel, or Microsoft’s Excel Community. Participate in challenges on platforms like ExcelJet, LeetCode, or Kaggle to improve your problem-solving skills and get insights from experts.
Additional Tips:
- Regularly practice on real-world datasets.
- Learn keyboard shortcuts to speed up your work.
- Explore Microsoft Excel's official documentation and free online tutorials for deeper insights.
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