SQL
Select all data from DB
SELECT * FROM <table_name>;
Select a column from table
SELECT <col name> FROM <table_name>;
Select multiple columns from table
SELECT <col name>, <col name> FROM <table_name>;
Change column name, making an alias
SELECT first_name AS" First name" FROM <table_name>;
SELECT first_name AS" First name", last_name AS Surname FROM table_name;
Retrieve specific information
SELECT <columns> FROM <table> WHERE <condition>;
SELECT first_name, last_name FROM people WHERE last_name = "Bloggs";
SELECT first_name, last_name FROM people WHERE last_name = "Bloggs" AND first_name = "Joe";
SELECT first_name, last_name FROM people WHERE last_name = "Bloggs" OR first_name = "Joe";
Compare multiple values
SELECT <columns> FROM <table> WHERE <condition> IN (value1, value 2, value 3);
SELECT * FROM people WHERE last_name IN ("Bloggs", "Shearer");
//opposite
SELECT * FROM people WHERE last_name NOT IN ("Bloggs", "Shearer");
Between a particular range
SELECT <columns> FROM <table> WHERE <columns> BETWEEN <minimum> AND <maximum>;
SELECT * FROM people WHERE age BETWEEN 1 AND 21;
Find data that matches pattern (has to contain a woldcard)
SELECT <columns> FROM <table> WHERE <columns> LIKE <whatever>
// % means any number of characters, search query is case insensitive
SELECT * FROM people WHERE name LIKE "%Shane%";
Filtering out or finding missing info
SELECT <columns> FROM <table> WHERE <columns> IS NULL;
SELECT * FROM people WHERE name = "Paul" AND age IS NULL;
SELECT * FROM people WHERE name = "Paul" AND age IS NOT NULL;
Refs
SQL basics Cheatsheet - Treehouse