Named_scope when using foreign keys

Rails
1

Hi all,

I can’t get this named scope to work. Each store has a number of
users. Each store can have one manager. I ant to use a nemed scope to
find the manager by name. Have I got this totally backwards?

Help appreciated
:slight_smile: jonas

class Store < ActiveRecord::Base
has_many :users, :dependent => :destroy
belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”
named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘manager.name = ?’, name ]}}

2

On 2 April 2010 09:06, jeb [email protected] wrote:

class Store < ActiveRecord::Base
has_many :users, :dependent => :destroy
belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”
named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘manager.name = ?’, name ]}}

You don’t say what errors you’re getting, but I’d suggest that if your
tables follow the naming conventions, the conditions should be:
:conditions => [‘managers.name = ?’, name ]

3

On 2 April 2010 09:06, jeb [email protected] wrote:

class Store < ActiveRecord::Base
has_many :users, :dependent => :destroy
belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”
named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘manager.name = ?’, name ]}}

That looks ok to me, assuming that the stores table has a manager_id
column. Remember that the named scope will return an array of stores
containing all the stores with a manager of that name.

If you have already a store in @store then to get the managers name
you just need @store.manager.name of course.

If that doesn’t help post the error you are getting and the code
around the error.

Colin

4

On 3 April 2010 11:42, jeb [email protected] wrote:

=> :users, :conditions => [‘users.name = ?’, name ]}}

class Store < ActiveRecord::Base
has_many :users, :dependent => :destroy
belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”
named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘manager.name = ?’, name ]}}

Has it included the managers table? You have not shown enough of the
sql to see. Try it with :include => :managers (plural)

Colin

5

Hi,

The error message is:
SQLite3::SQLException: no such column: manager.name: SELECT
“stores”.“id” AS t0_r0, “stores”.“customer_id” AS t0_r1, AND ON AND ON

There sure is a name column in the users model.

This works fine but does not give the same result of course:
named_scope :manager_name, lambda{|name| {:include
=> :users, :conditions => [‘users.name = ?’, name ]}}

:slight_smile: j

6

There is no managers table, just a relation. Thats the thing:

belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”

:slight_smile: j

7

On 7 April 2010 13:21, jeb [email protected] wrote:

There is no managers table, just a relation. Thats the thing:

belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”

So has it included the users table then? Post the whole sql.

Colin

8

class Store < ActiveRecord::Base
has_many :users, :dependent => :destroy
belongs_to :manager, :class_name => “User”, :foreign_key =>
“manager_id”
named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘manager.name = ?’, name ]}}

Had the same problem, try it with

named_scope :manager_name, lambda{|name| {:include
=> :manager, :conditions => [‘managers.name = ?’, name ]}}

with managers.name instead of manager,name the condition. worked for
me.