This is the main query that is needed for the OCR GCSE Specification in the exam. This is the query used to retrieve data stored in a database.
There are many other SQL queries but it is unlikely that you will be test on them.
Examples Queries
SELECT Queries with Wildcard
SELECT * FROM Customers;
This would select all the columns from the customer table.
SELECT Queries with where
SELECT Name, Telephone FROM Customers WHERE OrderID = 521;
This would select the Name and Telephone Columns from the Customers table for any record where the OrderId = 521;
SELECT Queries with Logical Operators
SELECT Name, Address FROM Customers WHERE Age > 55;
This would return the name and address of all cutomers who are over 55 years old
The best way to learn SQL is to just practice the queries. Have a go at these sites and learn some SQL!
SQL Zoo
Great for practice activities
w3Schools SQL
Another great site for practice
https://www.w3schools.com/sql/
SQL Island Game
Progress through this game by using SQL
http://wwwlgis.informatik.uni-kl.de/extra/game/