Re: Select from multiple tables
Kranthi Krishna <[email protected]>
| Newsgroups | gmane.comp.php.database |
|---|---|
| Message-ID | <CAJAheL61eosjjrOX19SuU9mPeEt9CP3bLUcy6pyfmP8U1RXpng@mail.gmail.com> |
Hi, Thanks for the input. I have seen some tutorials on joins, they all suggest that MySql returns multiple rows For example -------------------------- School | Board 1 -------------------------- School | Board 1 ------------------------- Now if I have another one-to-many relation ----------------------------------- School | Board 1 | Type 1 ----------------------------------- School | Board 1 | Type 2 ----------------------------------- School | Board 2 | Type 1 ----------------------------------- School | Board 2 | Type 2 ------------------------------------ Using UNIQUE or something similar (like php.net/array_search ) causes problems when Type 1 = Type 2 etc. Kranthi. http://goo.gl/e6t3 On 29 February 2012 19:43, Michael Stowe <[email protected]> wrote: > Select table1.item1, table2.item1 from table1 inner join table2 on table1.key = table2.foreignKey Where... > > You can also utilize left and right join to get data if there isn't a direct match (ie customer may not have ordered anything so you want to do a left join on orders as there may not be any order data but you still want to get the customer info). > > Hope that helps, > Mike > > > > Sent from my iPhone > > On Feb 29, 2012, at 8:01 AM, Kranthi Krishna <[email protected]> wrote: > >> Hi all, >> >> Say I have an object like >> >> array >> schoolName => string >> board => array >> string >> string >> >> I generally create two MySql tables >> >> schools: id PRIMARY KEY, SchoolName >> boards: id FOREGIN KEY refers Table A(id), board >> >> and then do two selects. The problem is that, the number of selects >> increase as the number of one-to-many relationships increase. >> >> Is there a better way to do this ? I have to extend an existing code >> so I cannot use any libraries like doctrine >> >> Kranthi. >> http://goo.gl/e6t3 >> >> -- >> PHP Database Mailing List (http://www.php.net/) >> To unsubscribe, visit: http://www.php.net/unsub.php >> -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php