[MySql] Joins on more than 2 tables

[figment]

Can anyone give me some working examples of how to to table joins on more than 2 tables? Or point me in the right direction?

[Frag]

like say...

SELECT a.customerid, b.invoicenumber, c.productid from table1 as a, table2 as b, table3 as c where a.customerid=b.customerref and b.orderedproduct=c.itemid;

This will join 3 items from 3 different tables.

[skodman]

Also You can do left and right join on several tables. sample code is like this

"select items.*,manufacturer, curr_name from items left join manufacturers on items.man_id=manufacturers.man_id, left join currency on items.curr_id=currency.curr_id where itemid=123"

Now this will give you at least one resulting row. If some of data is missing in joined tables (manufacturers and currency) for that field you will get "null". If you use right join then if some of thata is missing you will not get any result (this means that all fields called from joind tables have to have some value othervise you will not get any result).

skodman

[TTT]

or...

SELECT t3.id as id
FROM table3 t3 INNER JOIN table2 t2 ON t3.parent = t2.id
INNER JOIN table t ON t2.parent = t.id
WHERE t.content <> ""