search for: child_ids

I have this problem with records that have to be alligned on end- and startdate. I came up with the following. but am not convinced that this is the best way to tackle this problem. Anyone care for a braindump? def head_to_tail # Remove days that have startdate >= self.startdate AND enddate <= self.enddate # # before after # # |=====| |=====|

I'm trying to use sqldf to query for the earliest date of a blood test when patients have had multiple tests in a given year. My query looks like this: test11 <- sqldf("select CHILD_ID, min(SAMP_DATE) from lab group by CHILD_ID having extract (year from SAMP_DATE) = 2011") SAMP_DATE has class "date." I get the error

Hi all, I was wondering whether anyone could guide me to docu and code examples how to create and use a has_and_belongs_to_many relationship with a joining table where TWO columns are used to identify the relation to TWO alternative tables. Example: table 1: mothers [mother_id, name] table 2: fathers [father_id, name] table 3: children [child_id, name] joining table 4: children_parent

Hi: I''m trying to manually append objects to an instance variable that is just an array of objects. Here''s my controller code: @tasks = Task.find(:all, :conditions => "entity_id = #{session[:user].id}") for t in @tasks if Subtasks.find(:first, :conditions => "child_id = #{t.id}") != nil @mtasks << t end end However, when I execute, I

...tree in the console and I instantiated a new tree object and went to use the readline support to see all the available methods and I was rather surprised to see many many more methods than I was expecting..so I went to the api site and a lot of them weren''t documented.. .add_children, .child_ids, etc... now I can guess pretty easily what these methods do and my next step is to go and look at the source code...but can anyone suggest if i''m missing something? -- Posted via http://www.ruby-forum.com/.

I''m trying to set up a directional self-referential HABTM to represent an arbitrary semi-hierarchical structure; it works for any data prepopulated into the db, but when I try to create a new relationship, I just get NULLs in both key columns (or 0''s if I turn on the no-null constraint). Here are the migrations: class CreateNodes < ActiveRecord::Migration def self.up

Wine version: all Linux version: Fedora 3 and Gentoo 2.6.14 Symptom: When running quicken, opening the "Split costs" dialog causes the program to go into an infinite loop, flashingthe window to proper size then minimized and back again, as fast as the display will allow. It appears that the window is opened and the program attempts to flash the caret but access is denied to

How well does Rails deal with ActiveRecord classes mapping to self-referencing tables and other more interesting database complexities? i.e. Employees table with supervisor_id and mentor_id both self-referencing Employees on the primary key "id" or Categories table with relation table (Parent_Child_Categories) with foreign keys parent_id and child_id both referencing Categories.id

Hi I have a problem when sending parameters from link_to_remote. My link code: <%= link_to_remote "Remove", :url => object_relation_path( :id => 0, :object_relation => { :parent_id => @product.id, :parent_type => "Product", :child_id => content_object.id, :child_type => "ContentObject",

Basically, I''m trying to have a table called "categories" have a many to many relationship with itself. But I also want each catagory to be able to be "copied" into another category so it is essentially a child category to more than one parent. To me the obvious way of doing this is by creating another table called category_maps (and a model called CategoryMap).

Hi, New to Rails and the list. Quick questions regarding has_many relationships that require at least 1 child. I''m aware of validate_size_of and use this to make sure that the parent is not saved without at least one child. Question is, is there some Rails magic to help when removing children to ensure the last one is not removed? Currently I''m calling something like this in my

Hi i am trying to figure out what is the best way to do this very basic thing: lets say i have two tables: one with parents and one with children. there is a one to many relation between them. I scaffolded the parents tabel and i can open each parent. Now i want to add a link to the ''show'' view which will create a new child record. In the model i defined the has_many and

my application is using acts_as_tree to create a directed graph. Everyone would work fine, except that nothing prevents the user to create a circular reference: >> item.parent=child >> item.save => true >> child.parent=item >> child.save => true I checked in the database, and there it is: an item that has as parent its own child! item.parent_id = child_id I