SQL :: Using Joins (INNER JOIN, LEFT JOIN, RIGHT JOIN)

Understanding joins in SQL can save a lot of pain, the basics of any query is:

SELECT stuff
FROM table

When the table isn't enough, joins start showing up:

SELECT stuff, moreStuff
FROM table
INNER JOIN anotherTable ON table.key = anotherTable.foreignKey

The basics on how joins work:

• INNER JOIN
  selects all records where table.key = anotherTable.foreignKey

SELECT stuff, moreStuff
FROM table
INNER JOIN anotherTable ON table.key = anotherTable.foreignKey

• LEFT (OUTER) JOIN
  selects all records from table and any matches from anotherTable where anotherTable.foreignKey = table.key

SELECT stuff, moreStuff
FROM table
LEFT JOIN anotherTable ON table.key = anotherTable.foreignKey

• RIGHT JOIN
  selects all records from anotherTable and any matches from table where table.key = anotherTable.foreignKey

SELECT stuff, moreStuff
FROM table
LEFT JOIN anotherTable ON table.key = anotherTable.foreignKey