Problem linking tables and accessing relationship heirarchy

rubyonrails-talk
1

I'm reposting this her as somebody suggested I posted in the wrong forum before.

I'm not quite understanding this relationship thing between models and tables. What I am trying to do within my view is get the price information by referring to it like this:

<%= @item.itemprice.Qty1 %>

In each of my individual views for the item_master table and the itemprice table I can get the info directly, but I can't figure out how to access the price that corresponds to the item.

Here is my item.rhtml view test page:

2

The has_manys you've added mean that @item.itemprices will be an array of Itemprice objects, @item.itemprice (as you have found out) does not exist.

Fred

3

Frederick Cheung wrote:

[...]

The has_manys you've added mean that @item.itemprices will be an array of Itemprice objects, @item.itemprice (as you have found out) does not exist.

And what if there is a 1 to 1 relationship between tables? Then what statement would be used in the item_master.rb instead of has_many?

4

Frederick Cheung wrote:

[...]

The has_manys you've added mean that @item.itemprices will be an
array of Itemprice objects, @item.itemprice (as you have found out) does
not exist.

And what if there is a 1 to 1 relationship between tables? Then what statement would be used in the item_master.rb instead of has_many?

belongs_to or has_one (the difference is where the foreign key is
located - the documentation on associations has got a bit about this)

Fred

5

Frederick Cheung wrote:

belongs_to or has_one (the difference is where the foreign key is located - the documentation on associations has got a bit about this)

Fred

Thank you Fred,

That helped quite a bit. One problem is that I had a table called itemmaster with two fields one called ItemSerial and another called ItemMasterID. This caused confusion with Ruby/Rails because my foreign key was ItemSerial column.

I had to rename the ItemSerial field to id. Then when referencing the price table Ruby/Rails wanted to reference a column called item_master_id, so I had to rename my ItemSerial field to item_master_id in the price table.

This was all confusing with the naming since I have a different column called ItemMasterID that has nothing to do with the serial number.

It is confusing having to rename table columns, and not to be able to directly reference them instead of using the default naming assumption.

-Brian