# Object.find in HABTM join table? **URL:** \ **Category:** Rails\ **Created:** [July 15, 2010, 10:30am UTC](https://www.ruby-forum.com/t/object-find-in-habtm-join-table/191614 "2010-07-15T10:30:26Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![cojones](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/9f8e36/32.png) [@cojones](https://www.ruby-forum.com/u/cojones)\ **Post date:** [July 15, 2010, 10:30am UTC](https://www.ruby-forum.com/t/object-find-in-habtm-join-table/191614/1 "2010-07-15T10:30:26Z")
Good morning, is it possible to find objects by giving values for the HABTM join table only? Example: menu id name parents path 1 abc -1 / 2 def 1 /def 3 ghi 1 /ghi 4 jkl 2,1 /jkl 5 mno 2 /mno that means when I go to /abc the menu consists of menu items with the id 2, 3 and 4. When I go to /def the menu consits of the menu items with the id 4 and 5 but as you can see menu items can be shown in many menus but exist only once. So the tables would look like this: menus id name path 1 abc / 2 def /def 3 ghi /ghi 4 jkl /jkl 5 mno /mno menus\_parents menu\_id parent\_id 2 1 3 1 4 1 4 2 5 2 So how is it possible to all menu objects that have 1 as parent? My current approach is: menus = Menu.all menus = menus.select{|m| m.parents.include?(1)} I don’t really like it cause all menu items are loaded from the database each and every time. Is there any better solution to this like some find…? ---
**Author:** ![cojones](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/9f8e36/32.png) [@cojones](https://www.ruby-forum.com/u/cojones)\ **Post date:** [July 15, 2010, 12:18pm UTC](https://www.ruby-forum.com/t/object-find-in-habtm-join-table/191614/2 "2010-07-15T12:18:03Z")
On 15 July 2010 09:30, Heinz S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > 3 ghi 1 /ghi > id name path > 4 1 > 4 2 > 5 2 > > So how is it possible to all menu objects that have 1 as parent? > My current approach is: > menus = Menu.all > menus = menus.select{|m| m.parents.include?(1)} Can’t you do menus = Menu.find( :all, :include =\> :parents, :conditions =\> ['parent.id = ?, 1] ) or something similar. Or even better, if you have the parent object, then all the menus that have that as a parent are parent.menus Colin ---
**Author:** ![cojones](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/9f8e36/32.png) [@cojones](https://www.ruby-forum.com/u/cojones)\ **Post date:** [July 15, 2010, 3:22pm UTC](https://www.ruby-forum.com/t/object-find-in-habtm-join-table/191614/3 "2010-07-15T15:22:16Z")
Hey Colin, thanks but the parent.menus doesn’t work because the habtm is on the same table: has\_and\_belongs\_to\_many :parents, :class\_name =\> “Menu”, :association\_foreign\_key =\> “parent\_id”, :join\_table =\> “menus\_parents” The other suggestion works just fine, thanks! This is the working code: @menus = Menu.find(:all, :include =\> :parents, :conditions =\> [’`menus_parents`.parent\_id = ?’, parent.id]) ---
**Author:** ![cojones](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/9f8e36/32.png) [@cojones](https://www.ruby-forum.com/u/cojones)\ **Post date:** [July 15, 2010, 5:29pm UTC](https://www.ruby-forum.com/t/object-find-in-habtm-join-table/191614/4 "2010-07-15T17:29:34Z")
On 15 July 2010 14:22, Heinz S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hey Colin, > > thanks but the parent.menus doesn’t work because the habtm is on the > same table: > has\_and\_belongs\_to\_many :parents, :class\_name =\> “Menu”, > :association\_foreign\_key =\> “parent\_id”, :join\_table =\> “menus\_parents” I think there may be a better way of doing this. If you made the join table a proper table with a model then for Menu you could do has\_many children through menus\_parents and also has\_many parents through menus\_parents then you can go both ways more easily. Colin