SQL - Fundamentals 7

The goal of this quest series is to improve your SQL skills

Goals

• Improve your SQL skills

Codewars Katas

You need to resolve these three Codewars Katas

A little help

Single quote ' et double " quotes have different meanings in SQL.

• The single quote ' is used for filters and for cell contents, for example:

where table.column = 'my filter'

• The double quotes " is used for column names and aliases, for example:

select column as "my_column_name"
from table

Some SQL editors respect this rule more or less well, and are sometimes more flexible on the interpretation of the code. But it is better to learn this good practice.

Challenge - Codewars Katas

Once you have completed the katas, you can validate this quest yourself.