SQL Cheatsheet

Selecting Data:

Grab all columns:

SELECT * 
FROM table_name;

Grab specific columns

SELECT column1, column2, column3
FROM table_name
WHERE condition;

Joining data

Types of joins

• INNER JOIN returns only the rows where there is a match between the columns in both tables
• A LEFT JOIN returns all the rows from the left table and the matching rows from the right table
• A RIGHT JOIN returns all the rows from the right table and the matching rows from the left table

Outer joins add an additional layer of complexity. You can have a left or right outer join. An OUTER JOIN in SQL is used to return all the rows from one or both tables, including the non-matching rows

SELECT table_name_1.column_1, table_name_2.column_2
FROM table_name_1
INNER JOIN table_name_2
ON table_name_1.column_3 = table_name_2.column_3;

Command options

SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index