Listing of Category error


#1

Im trying to see posts index page, In tat im showing category list, im
using collect method it show error…

ActiveRecord::StatementInvalid in Posts#index
Showing app/views/posts/index.html.erb where line #19 raised:

Mysql::Error: Unknown column ‘categories_posts.category_id’ in ‘on
clause’: SELECT categories.* FROM categories INNER JOIN
categories_posts ON categories.id =
categories_posts.category_id WHERE ((categories_posts.post_id =
1))

Extracted source (around line #19):

16:

<%= post.created_at.strftime(’%m/%d/%y %I:%m %p’) %>
17: <%= h(post.title) %>
18: <%= h(post.author.display_name) if post.author %>
19: <%= post.categories.collect {|cat| [cat.name] }.join(",")
%>
20: <%= h(post.status) %>
21: <%= post.comments_count %>

pls help me, im new to RoR…??


#2

You must declare a has_many :categories in the Post model and a
belongs_to :post in the Category model (if the category table has a
post_id column, if not keep reading). If you don’t do that, you need
to create a categories_posts table with two columns: category_id and a
post_id.

Regards.

Franco C…


#3

Hi,

Im new to Ror, i want to do some userful website can u tell me ur
advice and wat steps i should to take basically in Ruby on Rails…??
then im trying to understand tat ( models, controller, action ) it
confusssed…
pls help me…

removed_email_address@domain.invalid


#4

You can read the Agile Web D. With Rails (http://
www.pragprog.com/titles/rails3), is a very good book. It explains step
by step the framework and a very common (but usefull) workflow.

Regards.

Franco C…