Conditionals

The WHERE clause is used to specify conditions of the queried result. It can be used with AND, OR and NOT for more complex conditionals.

The AND and OR operators are used for multiple conditions.

• AND evaluates to true when both sides of the condition are met.
• OR evaluates to true when ad least of the sides of the condition is met.

The NOT operator is used to specify when a condition is not true.

Syntax

SELECT <columns> FROM <table-name> WHERE <condition>

Example #1

SELECT name, founded, hq FROM Companies WHERE hq='United States'; 

Example #2

SELECT name, founded, hq FROM Companies 
WHERE founded=1998 OR hq='Canada'; 

Example #3

SELECT name, founded, hq FROM Companies 
WHERE hq='United States' AND 
(founded='1923' OR founded='1998'); 

Example #4

SELECT name, founded, hq FROM Companies 
WHERE hq='United States'
ORDER BY founded; 

Example #5

SELECT name, founded, hq FROM Companies 
WHERE NOT hq='United States';