many to many - Rails 4 - association not working correctly -

i created 2 models using rails generator this:

$ bin/rails g model manager name:string

and

$ bin/rails g model blog/post title:string manager:references

with that, have 2 models files:

# app/models/manager.rb class manager < activerecord::base     has_many :blog_posts end 

and

# app/models/blog/post.rb class blog::post < activerecord::base     belongs_to :manager end 

going rails console can create manager , post this:

$ manager1 = manager.new
$ manager1.name = "john doe"
$ manager1.save

$ post1 = blog::post.new
$ post1.title = "hello world"
$ post1.manager = manager1
$ post1.save

and on console, if do:

$ post1.manager.name

that works perfectly. returning manager's name. if do:

$ manager1.blog_posts

i expected list of manager's posts. getting error:

nameerror: uninitialized constant manager::blogpost

the same happing when try many-to-relationship between "blog:category (app/models/blog/category)" , "blog::post (app/models/blog/post.rb)"

update

@pavan solved first problem... , based in solution, tried this:

# app/models/blog/post.rb class blog::post < activerecord::base     belongs_to :manager     has_and_belongs_to_many :blog_categories, class_name: 'blog::category', foreign_key: 'blog_category_id' end 

and:

# app/models/blog/category.rb class blog::category < activerecord::base     has_and_belongs_to_many :blog_posts, class_name: 'blog::post', foreign_key: 'blog_post_id' end 

and based on http://guides.rubyonrails.org/association_basics.html#the-has-and-belongs-to-many-association, generate following migration:

class createblogcategoriesposts < activerecord::migration   def change     create_table :blog_categories_posts, id: false |t|       t.belongs_to :blog_post, index: true       t.belongs_to :blog_category, index: true     end   end end 

but when try on console:

$ post1 = blog::post.first
$ post1.blog_categories

i got error:

2.2.2 :002 > p.blog_categories pg::undefinedcolumn: error: column blog_categories_posts.category_id not exist line 1: ...log_categories_posts" on "blog_categories"."id" = "blog_cate... ^ : select "blog_categories".* "blog_categories" inner join "blog_categories_posts" on "blog_categories"."id" = "blog_categories_posts"."category_id" "blog_categories_posts"."blog_category_id" = $1 activerecord::statementinvalid: pg::undefinedcolumn: error: column blog_categories_posts.category_id not exist line 1: ...log_categories_posts" on "blog_categories"."id" = "blog_cate... ^ : select "blog_categories".* "blog_categories" inner join "blog_categories_posts" on "blog_categories"."id" = "blog_categories_posts"."category_id" "blog_categories_posts"."blog_category_id" = $1

nameerror: uninitialized constant manager::blogpost

you have has_namy :blog_posts defined in manager.rb, rails classname blogpost isn't exist in case.

you should explicitly specify classname tell rails use it.

# app/models/manager.rb class manager < activerecord::base   has_many :blog_posts, class_name: 'blog::post' end