How to join two tables in a single SQL query? MySQL Example

Hello guys, if you are wondering how to join multiple tables in SQL to produce a combine result which contains columns from all tables but not sure how to do it then you have come to the right place. SQL Join is one of the basic concepts while working in databases or tables but yet less understood and most confusing topic for beginners and even intermediate developers. I compare Joins in SQL  with Recursion in programming in terms of confusion because I have found that these two topics are special in their nature and you can't get it right with casual reading until you understand the concept and its various well.

How to Join Two Unrelated Tables in SQL using Cross Join? Example

 In one of the recent programming job interviews, one of my readers was asked the question, how do you join two tables which are not related to each other? i.e. they don't have any common column? is it possible in SQL? My reader got confused because he only knows about INNER join and OUTER join which require a key column like dept_id which is the primary key in one table like Department and foreign key in another table like Employee. He couldn't answer the question, though he did tell them about you can select data from multiple tables by typing multiple table names in from clause using a comma. 

Difference between Candidate Key vs Primary Key in Database/SQL

What is the difference between primary key and candidate key is another popular SQL and database interview question which appears in various programming interviews now and then? The concept of primary key and candidate key is not just important from the interview point of view but also in designing databases and normalization. By the way, this is my second post about primary keys, In the last one, we have seen a comparison of primary key vs unique key, which also happens to be one of the frequently asked database questions.

What is Difference between Clustered vs Non-Clustered Indexes in a table? [SQL Interview Question]

Hello guys, what is he difference between Clustered and Non-clustered index in a relational database is one of the most popular SQL interview questions almost as popular as the primary key vs unique key, the difference between truncate and delete, and correlated vs noncorrelated subqueries. Indexes are a very important concept, it makes your queries run fast and if you compare a SELECT query which uses an indexed column to one who doesn't you will see a big difference in performance.

Top 10 SQL Server Functions Programmer Should Learn (with Examples)

Hey there! SQL Server functions are like magic spells in the enchanted forest of databases. They can transform your data and make it dance to your tune. In this article, I'm going to share my top 10 SQL Server functions that every programmer should have in their toolkit.