SQL Reference

Chapter 2 | Supported standards 10
Field names can be prefixed with the table name or the table alias.
Example
Given the table specification FROM employee E, you can refer to the LAST_NAME field as
E.LAST_NAME. Table aliases must be used if the SELECT statement joins a table to itself.
SELECT * FROM employee E, employee F WHERE E.manager_id = F.employee_id
The equal sign (=) includes only matching rows in the results.
If you are joining more than one table, and you want to discard all rows that d
on’t have
corresponding rows in both source tables, you can use INNER JOIN.
Example
SELECT *
FROM Salespeople INNER JOIN Sales_Data
ON Salespeople.Salesperson_ID = Sales_Data.Salesperson_ID
If you are joining two tables, but you don’t want to discard rows of the first table (the “left” table),
you can use LEFT OUTER JOIN.
Example
SELECT *
FROM Salespeople LEFT OUTER JOIN Sales_Data
ON Salespeople.Salesperson_ID = Sales_Data.Salesperson_ID
Every row from the “Sales
people” table will appear in the joined table.
Notes
1 RIGHT OUTER JOIN is not currently supported.
1 FULL OUTER JOIN is not currently supported.