How to add/remove and modify column in a table?

 Hey there! Today, I'm going to share some DB wizardry that's incredibly handy in your SQL adventures: how to add, remove, and modify columns in a database table. Whether you're a seasoned data sorcerer or just starting your magical journey, this article has something for everyone.

Top 50 Database and SQL Interview Questions Answers for 2 to 5 Years Experienced

 Hello guys, whether you are preparing for Java developer interview or any other Software Developer Interview, a DevOps Interview or a IT support interview, you should prepare for SQL and Database related questions. Along with Data Structure, Algorithms, System Design, and Computer Fundamentals, SQL and Database are two of the essential topic for programming or technical Job interview. In the past, I have shared many questions related to MSSQL questions, Oracle Questions, MySQL questions, and PostgreSQL questions and in this article, I am going to share both theory based and query based Database and SQL Interview questions with to the points answers.

Difference between 1NF, 2nd NF, 3rd NF and BCNF? Normalization Example Tutorial

Normalization is one of the essential concept of relational database. It is the process or technique to remove duplicate data from tables and thus reduce the storage size. It also helps to maintain integrity of data. Normalization likewise assists with coordinating the information in the data set. It is a multi-step process that sets the information into even structure and eliminates the copied information from the relational tables. 

Difference between Primary key Unique key in Database SQL

Hello friends, both primary key and unique key are two important concepts in a relational database which are used to uniquely identify a row in a table. For example, EmployeeId is often primary key in Employee table which can uniquely identify any employee which is denoted by a row in Employee table. Similarly, a employee can also be identify with EmployeeName if there is no duplicate but if its not primary key then we call it a unique key. While both primary key and unique keys can identify a row uniquely but there is some subtle difference between them which we will see in this article. 

Does order of columns matter in composite index? Examples

Hello guys, if you have worked in SQL then you may know that indexes are very important and that's why they are also quite popular on SQL interviews. One of such question which I remember asked to me on interview was "does the order of columns matters in case of composite index?" I mean if you have an index which depends upon two columns the does the order mater like A, B or B,A are same or different. It's tricky question and not many people can answer but we will try in this article.  When it comes to composite indexes, the order of columns can significantly impact how efficiently a database executes queries. In this article, we'll explore the implications of column order in composite indexes and provide examples to illustrate its influence on SQL optimization.