Showing posts with label JOIN. Show all posts
Showing posts with label JOIN. Show all posts

Tuesday, June 3, 2025

Difference between Equi Join and Non-Equi Join in SQL with Examples

Hello guys, If you want to learn about the difference between Equi and Non-Equi join in SQL then you have come to the right place. Earlier, I have shared the difference between LEFT and RIGHT join in SQL and now we will understand equi and non-equi join in SQL and database. The term "Non-Equi join" in SQL Server may sound abstract, but it's far from it. Equi joins are the same way. I think you'll agree with me after reading this essay. I'll attempt to explain what they are and when they should be used today. So, let's get this party started. 

Friday, May 16, 2025

How to use LEFT, RIGHT, INNER, OUTER, FULL, and SELF JOINs in SQL? Example Tutorial

What are joins and why are they required?

Hello, everyone. Have you ever faced any issues while generating reports or loading data but were using data of just one table was not enough? One table's data is typically insufficient to provide important insights when doing sophisticated analytical processing and data discovery, therefore merging numerous tables is required. SQL, as a method for communicating with relational databases, allows you to create relationships between tables

Saturday, February 22, 2025

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.

Thursday, February 20, 2025

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. 

Wednesday, October 23, 2024

SQL cross join Example and it's performance

Hello guys, in the past, I gave you a quick overview of SQL JOINS where we learned about different types of JOINS like right, left, inner, and outer join, and in this article, we'll learn about the SQL CROSS JOIN idea in this post, and we'll back up our knowledge with simple examples and illustrations. So, let's start with the basics.

Wednesday, September 4, 2024

How to join two unrelated tables in SQL? 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. 

Friday, August 30, 2024

How to use JOIN Multiple Tables in MySQL? Example Tutorial

 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. Things get worse when the table locked due to such SQL Join queries which were fired without knowing how much time it would and how big the result set could be. 

Wednesday, August 28, 2024

Difference between Self and Equi Join in MySQL

 The main difference between Self Join and Equi Join is that In Self Join we join one table to itself rather than joining two tables. Both Self Join and Equi Join are types of INNER Join in SQL, but there is a subtle difference between the two. Any INNER Join with equal as join predicate is known as Equi Join. SQL Joins are the fundamental concept of SQL similar to correlated and noncorrelated subqueries or using group by clause and a good understanding of various types of SQL join is a must for any programmer.