How to get values from different table using association in rails? - ruby-on-rails

Question

I've two tables in my Postgres database structures given below:
CREATE TABLE tables(
id serial NOT NULL,
name character varying(255),
table_state_id integer,
table_type integer,
CONSTRAINT tables_pkey PRIMARY KEY (id)
)
AND
CREATE TABLE table_states
(
id serial NOT NULL,
name character varying(255),
CONSTRAINT table_states_pkey PRIMARY KEY (id)
)
Table Model :
class Table < ActiveRecord::Base
attr_accessible :name, :table_type, :table_state_id,
belongs_to :table_state
end
TableState Model:
class TableState < ActiveRecord::Base
attr_accessible :name, :color_code
has_many :tables
end
In View I'm accessing like that:
= debug #table_data.table_state.name # Where `#table_data` is a variable from `tables` table
Through association I want to access name column of table_states table whose ID is present in table_state_id column of tables table. How can I do it?

Answer 1

You are having everything right in your code. There must be nil saved in your table_state_id in your tables table.
Error indicates that your table_state associated object is nil. this #table_data.table_state will return table_state object and error referring this to nil.
Try run select table_state_id from tables on your db console and see results. And make necessary changes in record through db console.
For future you can also use try to rescue such problem (specially production mode)
= debug #table_data.table_state.try(:name)