Update Realtion

Hi I want to assign continents to my products with a drop down box.
I managed to get everyting runing but now i have a probably quite easy
to solve problem.
I don’t get the update running.

What want to do is basically:
SELECT * FROM “continents” WHERE (“continents”.“id” = “continent_id”)
LIMIT 1

But I don’t find the right syntax.

At the moamnt it looks like this:
SELECT * FROM “continents” WHERE (id = ‘— :continend_id’) LIMIT 1

The parameters of my update are looking like this:
Parameters: {“commit”=>“Update”, “action”=>“update”, “_method”=>“put”,
“authenticity_token”=>"***", “product”=>{“image_url”=>“w.jpg”,
“expirience_points”=>“0”, “price”=>“1”, “title”=>“w”,
“description”=>“w”, “continent_id”=>“7”}, “id”=>“11”,
“controller”=>“products”}

This is the code of may update methode:
def update
@product = Product.find(params[:id])
@product.continent = Continent.find(:first, :conditions => [ “id =
?”,:continend_id ])
if @product.update_attributes(params[:product])
flash[:notice] = ‘Product was successfully updated.’
redirect_to(@product)
else
render :action => “edit”
end
end

Hi Ma We,

On Tue, Jun 8, 2010 at 5:23 AM, Ma We [email protected] wrote:

@product.continent = Continent.find(:first, :conditions => [ “id =
?”,:continend_id ])

You haven’t posted what you’re getting as a result, but one problem is
that you don’t have a variable named continend_id in your code. You
have a params element named continent_id. Change the Continent.find
clause to use :params[:continent_id]. A couple of other tips.

I always use .to_i on finds where I’m using a param since they’re
strings and find takes an integer. It helps to remind me that params
are strings.

Your Continent.find could be shortened to
Continent.find(params[:continent_id].to_i)

HTH,
Bill

Thanks for your answer.

I tried already:
:params[:continent_id] //Error: Couldn’t find Continent with ID=0

the problem is that :continent_id is the foreign key in products and i’m
looking for the :id in continents which is the same then :continent_id

I also tried to use:
-:params[:continent_id].to_i //which comes out the same like
:params[:continent_id]
-:continent_id.to_i //Error: Couldn’t find Continent with ID=103233
-:first, :conditions => [ “id = ?”,:continend_id.to_i ]) //the same then
above except that it don’t brings the error because it just doesn’t find
ID=103233 and returns nil

The problem with :continent_id.to_i is that it is not casting the number
value which should put in the case above 7 out.

  • @product.continent = Continent.find(:first, :conditions => [ “id =
    ?”,:continend_id ]) //returns nil the SQL looks like this SELECT * FROM
    “continents” WHERE (id = ‘— :continend_id’) LIMIT 1

Hi Marcus,

On Tue, Jun 8, 2010 at 6:39 AM, Markus W. [email protected]
wrote:

Thanks for your answer.

You’re welcome.

-:first, :conditions => [ “id = ?”,:continend_id.to_i ]) //the same then

Are you sure it’s not just a typo?

continend_id vs continent_id

Best regards,
Bill

You are right there was a typo but didn’t change anything.
to make sure I tried :id.to_i witch brings 3049 instead of 1

-:first, :conditions => [ “id = ?”,:continend_id.to_i ]) //the same then

Are you sure it’s not just a typo?

continend_id vs continent_id

Marnen Laibow-Koser wrote:

You’re trying to pass a symbol instead of a variable into your query
string, so of course it won’t work. What you want is
[“id = ?”, continent_id.to_i] (without the colon).

But you should never need to do it this way. For a simple equality
check, use the hash syntax:
{:id => continent_id.to_i}
or consider find or find_by_id .

Ok I do understand now the Problem with the Symbols.
But with @product.continent = Continent.find({:id => continent_id.to_i})
I get
undefined local variable or method `continent_id’
waht I do understand because I’m in def update and the parameters witch
are passed are:

Parameters: {“commit”=>“Upd… ,
“product”=>{“image_url”=>”/images/Burger.png",
“expirience_points”=>“10”, “price”=>“1.99”, “title”=>“WHOPPER®”,
“description”=>"…", “continent_id”=>“7”}, “id”=>“1”,
“controller”=>“products”}

But how do I get now from :product the “continent_id”=>“7”

Markus W. wrote:

You are right there was a typo but didn’t change anything.
to make sure I tried :id.to_i witch brings 3049 instead of 1

-:first, :conditions => [ “id = ?”,:continend_id.to_i ]) //the same then

You’re trying to pass a symbol instead of a variable into your query
string, so of course it won’t work. What you want is
[“id = ?”, continent_id.to_i] (without the colon).

But you should never need to do it this way. For a simple equality
check, use the hash syntax:
{:id => continent_id.to_i}
or consider find or find_by_id .

Are you sure it’s not just a typo?

continend_id vs continent_id

Best,

Marnen Laibow-Koser
http://www.marnen.org
[email protected]

The answer is
Continent.find(params[:product][“continent_id”])

in more Steps

first=params[:product]
second=first[“continent_id”]
Continent.find(secon)

May be there is a better way as well but any way it works finally.

thanks to for Helping to get on the right way!

Markus W. wrote:
in def update and the parameters witch

are passed are:

Parameters: {“commit”=>“Upd… ,
“product”=>{“image_url”=>”/images/Burger.png",
“expirience_points”=>“10”, “price”=>“1.99”, “title”=>“WHOPPER®”,
“description”=>"…", “continent_id”=>“7”}, “id”=>“1”,
“controller”=>“products”}

But how do I get now from :product the “continent_id”=>“7”