Model Associations

Hi,

I have just started using rails and i am trying to use IP database to get user location.

Here are the database schemas...

[code]CREATE TABLE IF NOT EXISTS `ip_group_cities` (   `ip_start` bigint(20) NOT NULL,   `location` int(11) NOT NULL,   UNIQUE KEY `index_ip_group_cities_on_ip_start` (`ip_start`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE IF NOT EXISTS `iso3166_countries` (   `code` varchar(2) NOT NULL,   `name` varchar(64) NOT NULL,   UNIQUE KEY `index_iso3166_countries_on_code` (`code`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE IF NOT EXISTS `locations` (   `id` int(11) NOT NULL AUTO_INCREMENT,   `country_code` varchar(2) NOT NULL,   `region_code` varchar(2) NOT NULL,   `city` varchar(64) NOT NULL,   `zipcode` varchar(8) NOT NULL,   `latitude` float NOT NULL,   `longitude` float NOT NULL,   `metrocode` varchar(3) NOT NULL,   PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;[/code]

and here is the sql [code]SELECT locations.city,locations.id FROM ip_group_cities,locations where ip_group_cities.ip_start <= INET_ATON('$ip') AND ip_group_cities.location = locations.id order by ip_group_cities.ip_start desc limit 1[/code]

i have used these associaltions

[code]class Iso3166Country < ActiveRecord::Base   has_many :locations, :foreign_key: :id end [/code]

[code]class IpGroupCity < ActiveRecord::Base   has_one :locations, :foreign_key => :id end [/code]

[code]class Location < ActiveRecord::Base   has_many :ip_group_cities, :foreign_key => :location   belongs_to :iso3166_countries, :foreign_key => :country_code end [/code]

But when i run this code

[code] C = Location.find(1); [/code]

It does not show me the columns from the other tables... I mean i dont see a name column from the Iso3166Countries table.

What am i doing wrong?

C = Location.find(1);

It does not show me the columns from the other tables… I mean i dont see a name column from the Iso3166Countries table.

All you are asking rails to do is load a location object - what were you expecting it to do?

Fred

Hi,

I have just started using rails and i am trying to use IP database to get user location.

Here are the database schemas...

[code]CREATE TABLE IF NOT EXISTS `ip_group_cities` ( `ip_start` bigint(20) NOT NULL, `location` int(11) NOT NULL, UNIQUE KEY `index_ip_group_cities_on_ip_start` (`ip_start`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE IF NOT EXISTS `iso3166_countries` ( `code` varchar(2) NOT NULL, `name` varchar(64) NOT NULL, UNIQUE KEY `index_iso3166_countries_on_code` (`code`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE IF NOT EXISTS `locations` ( `id` int(11) NOT NULL AUTO_INCREMENT, `country_code` varchar(2) NOT NULL, `region_code` varchar(2) NOT NULL, `city` varchar(64) NOT NULL, `zipcode` varchar(8) NOT NULL, `latitude` float NOT NULL, `longitude` float NOT NULL, `metrocode` varchar(3) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;[/code]

and here is the sql [code]SELECT locations.city,locations.id FROM ip_group_cities,locations where ip_group_cities.ip_start <= INET_ATON('$ip') AND ip_group_cities.location = locations.id order by ip_group_cities.ip_start desc limit 1[/code]

i have used these associaltions

[code]class Iso3166Country < ActiveRecord::Base has_many :locations, :foreign_key: :id

What is the foreign_key spec here supposed to be doing?

end [/code]

[code]class IpGroupCity < ActiveRecord::Base has_one :locations, :foreign_key => :id

If you really mean has_one then it should be :location (singular). I suspect you mean belongs_to however since you have location has_many IpGroupCities below. Again what is the foreign_key spec for?

end [/code]

[code]class Location < ActiveRecord::Base has_many :ip_group_cities, :foreign_key => :location

Again I do not understand the foreign key spec

belongs_to :iso3166_countries, :foreign_key => :country_code end [/code]

But when i run this code

[code] C = Location.find(1);

You would be better to use lower case C.

[/code]

It does not show me the columns from the other tables... I mean i dont see a name column from the Iso3166Countries table.

Try C.iso3166_country. It will not fetch the association data until you ask.

Colin