SELECT

Microsoft SQL Server  SELECT TOP 10 column FROM table

PostgreSQL and MySQL  SELECT column FROM table LIMIT 10

Oracle  SELECT column FROM table WHERE ROWNUM <= 10

Sybase  SET rowcount 10 SELECT column FROM table

Firebird  SELECT FIRST 10 column FROM table

내부 조인

select customers.CustomerNumber, orders.Amount, items.Description

FROM customers JOIN orders ON (customers.CustomerNumber = orders.CustomerNumber)

JOIN items ON (orders.ItemNumber = items.ItemNumber)

외부 조인

select customers.CustomerNumber, orders.Amount, items.Description

FROM customers LEFT OUTER JOIN orders ON (customers.CustomerNumber = orders.CustomerNumber)

LEFT OUTER JOIN items ON (orders.ItemNumber = items.ItemNumber)

select customers.CustomerNumber, orders.Amount

FROM orders RIGHT OUTER JOIN customers ON (customers.CustomerNumber = orders.CustomerNumber)

select customers.CustomerNumber, orders.Amount

FROM customers FULL OUTER JOIN orders ON (customers.CustomerNumber = orders.CustomerNumber)