# Searching database using foriegn keys **URL:** \ **Category:** Rails\ **Created:** [March 10, 2006, 4:05am UTC](https://www.ruby-forum.com/t/searching-database-using-foriegn-keys/54618 "2006-03-10T04:05:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jjrussell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@jjrussell](https://www.ruby-forum.com/u/jjrussell)\ **Post date:** [March 10, 2006, 4:05am UTC](https://www.ruby-forum.com/t/searching-database-using-foriegn-keys/54618/1 "2006-03-10T04:05:43Z")
I’ve read a lot about the ORM magic of Active Record which allows you to address a foriegn key object directly… e.g. I have a books and people table where books has a column called person\_id If I get myself a Book object called mybook I get to the person object associated with this book by saying book.person which is awesome and I love it. My question, how can I say "Go and get me all the books whose person = “Andy Griffith”. See what I mean? I want to search for a bunch of book rows based on some value in the people table. How can I do that? Thanks. ---
**Author:** ![jjrussell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@jjrussell](https://www.ruby-forum.com/u/jjrussell)\ **Post date:** [March 10, 2006, 5:26am UTC](https://www.ruby-forum.com/t/searching-database-using-foriegn-keys/54618/2 "2006-03-10T05:26:42Z")
On Mar 9, 2006, at 7:05 PM, John R. wrote: > rows based on some value in the people table. How can I do that? > person.books – – Tom M. ---
**Author:** ![jjrussell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@jjrussell](https://www.ruby-forum.com/u/jjrussell)\ **Post date:** [March 10, 2006, 9:53am UTC](https://www.ruby-forum.com/t/searching-database-using-foriegn-keys/54618/3 "2006-03-10T09:53:17Z")
Hi John, > My question, how can I say "Go and get me all the books whose person = > “Andy Griffith”. See what I mean? I want to search for a bunch of book > rows based on some value in the people table. How can I do that? > Thanks. Try: Person.find\_by\_name(“Andy Griffith”).books This assumes that your people database table has a column called “name”, otherwise simple replace name by whatever your column is called (e.g Person.find\_by\_fullname). Or if you did split firstname/lastname in your database Person.find\_by\_firstname\_and\_lastname(‘Andy’, ‘Griffith’).books Matt ---
**Author:** ![jjrussell](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@jjrussell](https://www.ruby-forum.com/u/jjrussell)\ **Post date:** [March 10, 2006, 4:04pm UTC](https://www.ruby-forum.com/t/searching-database-using-foriegn-keys/54618/4 "2006-03-10T16:04:41Z")
Matthias von Rohr wrote: > Hi John, > > > My question, how can I say "Go and get me all the books whose person = > > “Andy Griffith”. See what I mean? I want to search for a bunch of book > > rows based on some value in the people table. How can I do that? > > Thanks. > > Try: > > Person.find\_by\_name(“Andy Griffith”).books > > This assumes that your people database table has a column called “name”, > otherwise simple replace name by whatever your column is called (e.g > Person.find\_by\_fullname). > Or if you did split firstname/lastname in your database > > Person.find\_by\_firstname\_and\_lastname(‘Andy’, ‘Griffith’).books > > Matt Thanks for both responses. I put in a simpler example than I needed to make it easier to explain. This is very good, but what if there are several foreign keys for the books table. e.g. I want to do a search to find all the books that where person from the people table = Andy Griffith, publisher from the publishers table = Westinghouse, printer from the printers table = Bob’s printing etc. In other words, several conditions based of foreign keys at the same time. Exactly like conditions works for the find method except with foriegn keys. Am i reaching here? The only other thing I can think of is to look up each foriegn key individually and then put the id’s into the conidtion of books.find but that seems to be working around the ORM. Of course, using like a search engine is abusing it to begin with… Is that more clear? Thanks again.