MySQL Basics

Syntax

SELECT name, city
FROM customers
WHERE country = 'Mexico';
ORDER BY postalcode ASC;

Basics

It is not case sensitive (yay! select is the same as SELECT) and some db require semicolon ( ; ) at the end of SQL statement.

To retrieve information from the database we use the command SELECT. SELECT * retrieves everything.

Operators

AND, OR, NOT

Keywords and statements

ORDER BY ASC
ORDER BY DESC

GROUP BY

Example: SELECT COUNT(CustomerID), Country FROM Customers GROUP BY Country ORDER BY COUNT(CustomerID) DESC;

Functions

MIN()
MAX()
COUNT()    number of rows
AVG()
SUM()

Example: SELECT MIN(Price) AS SmallestPrice FROM Products;

Clauses and operators

WHERE 
    equal        =
    not equal     <>
    multiple values IN ('a','b')
    ranges        BETWEEEN x AND y 
    pattern       LIKE 'a%'
    operators     >, <, >=, <=
        condition1 AND condition2
        condition1 OR condition2
        NOT condition
        IS NULL
        IS NOT NULL

Examples:
SELECT * FROM Customers
WHERE City IN ('Paris','London');

SELECT * FROM Products
WHERE Price BETWEEN 50 AND 60;

SELECT * FROM Customers
WHERE City LIKE 's%';
    > Strasbourg, Sao Paulo, Sevilla...

Wildcards

a%
%a
%ab%
a_%_%