SQL beginners can have some problems with understanding how Self-Join works. But everybody should understand
how handy this query type is. It helps us to combine two records inside same table into single row.

This thing is widely used on some level of programming and for sure we all sure understand, how to use it.

Sometimes you can realize, one query is not enough to get the information you want.
It just feels like you need to do it "in steps". Thank god, we have Subqueries in SQL.

Subqueries will help you make more complex SQL queries and i will show you how to write them.

In the previous article we were talking about INNER JOINS. Today we will try to understand OUTER JOINS with all their types.

If you want to understand how they work - this is place for you, just click Read more :)

INNER JOIN is the simplest JOIN type and if you want to understand the clue of using JOINS,
you definitely should start from this point.

In this article i will show you how to use INNER JOIN and explain when to use it properly.

Sometimes you want to change the column name to make it more readable and easier to analyze.

AS clause will fit all your expectations in this field

This article will help you with understating GROUP BY and HAVING commands inside SQL language.