Review - Is Data Science Fundamentals with Python and SQL Specialization on Coursera Worth It in 2025?

The demand for people who can analyze big data and extract meaningful information to drive decisions for companies is increasing every day. They need them to improve the quality of their services and deliver the best user experience for their customers. These actions are the responsibility and the role of the data scientists. Data scientists need to know many skills to perform the data analysis and make decisions such as the skills to collect data from different sources like the web and also extract and filter the data from the databases and clean them before performing analysis and even learn machine learning and deep learning to perform much more complex actions and make predictions but not all the data scientists know the artificial intelligence and not a mandatory skills. Still, it will be good if you have that in your belt.

5 Free SQL Books For Beginners and Experienced in 2025 - Download PDF or Read Online

There is no doubt that SQL is one of the most essential skills for Programmers, IT professionals, Software Engineers, Quality Analysts, Project Manager, Data scientists, Database admins, and Business Analysts. I had even mentioned this as one of the top skills in my post about 10 things every programmer should know, if you haven't read that yet, you can read it here, it's completely worth your time. Since many Enterprise applications use the relational database at their backend, like Oracle, Microsoft SQL Server, MySQL, it's crucial to learn SQL to work with those applications and use the data stored on those databases.

Top 5 Free Microsoft SQL Server Books in 2025 - PDF Download or Online Read

Hello Guys, if you want to learn SQL Server and looking for free resources then you have come to the right place. Earlier, I have shared free SQL and database courses and today, I am going to share some of the excellent database and SQL server books that are freely available on the internet for reading online or download as PDF. If you have been reading this blog then you know that I love books, I love to read books, and I love to collect books, that's why I have a significant online and offline library. Many people question me, do I really find to read all the books which I share? Well, I don't read all books page by page, unless and until it's something like Effective Java or Clean Code.

How Long It Take To Become a DBA (Database Administrator) in 2025?

Hello guys, if you want to become a Database Administrator in 2025 and wondering how long does it take to learn SQL and Database and become a professional Database Administrator or Junior DBA then you are at right place. In the past, I have shared free SQL and Database courses as well roadmap to become a Web Developer and in this article, I am going to share how long it will take you to become a DBA in 2025. Along the way, I will share best way to learn SQL and Database and what is the best way to become a DBA quickly. So continue reading and find out what it takes to become a DBA and get a job in real world. I will also share all the skills you need to become a DBA in 2025.

Top 7 Books to learn SQL and Database Design in 2025 - Best of Lot

SQL (Structured Query Language) is one of the most essential skills of a programmer. I would rate this skill similar to UNIX if you are a professional programmer because it doesn't matter whether you are Java, C++, or a .NET developer, you are bound to write SQL queries. Since a database is an integral part of any modern Java or Web application, the Interviewer always preferred candidates with excellent SQL skills. Now, the big question comes, how a programmer can learn SQL? Does just knowing how to query a table is enough? If you remember, insert, update, delete, and select, then are you a competent SQL programmer?

Top 6 Free Database and SQL Query Courses for Beginners to Learn Online in 2025 - Best of Lot

Hello guys, I have been sharing some free programming resources e.g. books and courses in this blog for quite some time. Earlier I have shared free courses on Java, Maven, Spring, and Data Structure and Algorithms and today I'll share some of the free online training courses to learn SQL and Database. Why you should learn SQL? Well, it's one of the must-have skills for programmers, application developers, and IT professionals. Like Linux, this is one skill that is going to serve you longer than any other programming language, framework, or library.

Top 6 SQL and Database Courses on Udemy + Coursera in 2025 - Best of Lot

Hello guys, if you want to learn SQL and Database and look for the best Udemy courses, you have come to the right place. Earlier, I have shared the best free SQL courses, which contain free courses from Udemy and Coursera, and other websites. This article will share the best SQL courses from Udemy, suitable for beginners and intermediate developers. SQL has been a vital tech skill for a long time, but with the advent of Data Science and Data Analysis, the importance of data has made it even more critical in today's world.

Top 5 Free Coursera Courses for SQL and Database in 2025 - Best of Lot [UPDATED]

Hello guys, if you want to learn SQL and Database and looking for best free resources like books, online courses and websites then you have come tot he right place. Earlier, I have shared best SQL courses, SQL books, and best websites to learn SQL and in this article, I am going to share best free SQL courses from Coursera, one of the best place to learn technical skill from world's top university and companies online. While many people are familiar with Coursera courses and certifications then don't know that most of the Coursera courses can be taken for free-to-audit where you can watch them for free without enrolling on specialization or professional certification. Only thing is you don't have access to quizzes and exercise sand you don't get certificate but you can still learn from worlds' top trainers and instructors.

Top 10 Frequently asked SQL Query Interview Questions Answers

In this article, I am giving some examples of SQL queries which is frequently asked when you go for a programming interview, having one or two year experience in this field. Whether you go for a Java developer position, QA, BA, support professional, project manager, or any other technical position, may interviewer expects you to answer basic questions from Database and SQL. It's also obvious that if you are working for one or two years on any project there is a good chance that you come across to handle databases, writing SQL queries to insert, update, delete and select records.

Difference between Correlated and Non-Correlated Subquery in SQL? Examples

Hello guys, the difference between correlated and non-correlated subquery is one of the popular SQL interview question and an important concept for any programmer to learn. The correlated subquery is one of the tricky concepts of SQL. It's similar to recursion in programming which many programmers struggle to understand, but like recursion, it also offers the unique capability to solve many SQL query-based problems like the second-highest salary problem where you need to compare one row of the table to another row. It gives you a different kind of power. The main difference between a regular, non-correlated, and correlated subquery in SQL is in their working, a regular subquery just runs once and returns a value or a set of values that is used by the outer query.

Second Highest Salary in MySQL and SQL Server - LeetCode Solution

Write a SQL query to get the second highest salary from the Employee table.

+----+--------+
| Id | Salary |
+----+--------+
| 1 | 100 |
| 2 | 200 |
| 3 | 300 |
+----+--------+

For example, given the above Employee table, the second highest salary is 200. If there is no second highest salary, then the query should return NULL. You can write SQL query in any of your favorite databases e.g. MySQL, Microsoft SQL Server, or Oracle. You can also use database specific feature e.g. TOP, LIMIT or ROW_NUMBER to write SQL query, but you must also provide a generic solution which should work on all database.

Difference between ROW_NUMBER(), RANK() and DENSE_RANK() in SQL

The main difference between ROW_NUMBER() and RANK() in SQL server is that ROW_NUMBER doesn't handle ties while RANK() does. Though both ROW_NUMBER() and RANK() are window function used for ranking row, the way they handle duplicates differentiate them. ROW_NUMBER() function assigns a unique number to each row starting from 1 and arbitrarily assign values if two rows are equal, which means it's not guaranteed that which row will get 2nd or 3rd position if they are identical. In contrast, RANK() assigns an equivalent rank to similar rows, which creates gaps between RANK.

Difference between VARCHAR and CHAR data type in SQL Server? [Explained]

Hello all, today, I am going to share an interesting SQL Server interview question, which will not only help you in your interview but also in your day-to-day work. It explains one of the critical concepts of SQL Server, the difference between VARCHAR and CHAR data type. I am sure, you all have used both of them numerous times but because it's so common many of us ignore the difference between them and when asked to choose between VARCHAR and CHAR on interviews, they fail to give a convincing reason. The difference is not just significant from an interview point of view but also from a robust database design because an incorrect choice of data type not only limit what kind of data you can put on but also waste precious space and makes your query slower, particularly when you have to deal with the massive amount of data.

What is window function in SQL with Examples? How and when to use them?

Hello folks, if you are wondering what is window function and what problem does it solve then you have to the right place. In this article, I would be explaining the windows functions with examples, how it works, and when you need to use it. Firstly what is a Window Function in SQL? A window function performs a calculation across a set of table rows that are similarly related to the current row. The current row is the row in which function evaluation occurs. This is comparable to the type of calculation that can be done with an aggregate function. But unlike regular aggregate functions like sum, avg, max, and min, that perform operations on an entire table.

Top 20 PL/SQL Interview Questions with Answers

Hello guys, if you are preparing for Oracle or PL/SQL Job or a Developer job where PL/SQL skills are needed and looking for frequently asked PL/SQL Interview Questions then you have come to the right place. Earlier, I have shared both best PL/SQL courses and best PL/SQL books and in this article, I am going to share popular PL/SQL Interview Questions you can revise before your interview. Preparing for PL/SQL Interview is not a rocket science and you can prepare for it the same way you prepare for other interviews.

How to use DROP command to remove tables in Oracle, MySQL and SQL Server

Hello guys, if you want to learn about DROP command in SQL then you have come to the right place. Earlier, I have shared the best free SQL and Database courses and several tutorials to learn SELECT, GROUP BY, and other important commands, and in this article, I will show you to use the DROP command in SQL. DROP is one of the basic SQL commands, which is used to DROP database objects. Since it's part of ANSI SQL, the DROP command is supported by all major database vendors, including Oracle, MySQL, and Microsoft SQL Server. A SQL DROP TABLE statement is used to delete a table definition and all data from a table, but DROP can also be used to drop index, view, trigger, or any other database object.

10 Essential SQL Commands and Functions Every Developer should learn

Hello guys, if you are starting with SQL and wondering which commands you should learn first then you have come at the right place. In this article, I have shared 10 most essential SQL commands and functions which I believe every programmer should learn. This includes commands to pull data from database as well write data into data, update data, and remove data from database. While writing in the SQL language, you will utilize an assortment of SQL keywords to make explanations and questions. An assertion includes a series of characters and SQL keywords that adjusts to the designing and grammar rules of the language and may influence information or control processes corresponding to your information.

How to convert String to Integer SQL and Database? MySQL, Oracle, SQL server and PostgreSQL Example

Hello guys, if you are wondering how to convert VARCHAR to String in SQL then you are at the right place. In this article, we will cover various techniques to convert String to Integer in all databases - MySQL, Oracle, SQL server and PostgreSQL. To perform tasks or correlations or change between information in a SQL Server data set, the SQL information kinds of those values should coordinate. At the point when the SQL information types are unique, they will go through a cycle called type-projecting. The transformation of SQL information types, in this cycle, can be implied or unequivocal.

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Top 5 PostgreSQL Courses and Tutorials for Beginners in 2025 - Best of Lot