update after delete row in ruby on rails -

two models have created i.e "user" , "communication", , schema below:

user model scheme: id | name | email       | skilltype     | user_need 1  | ijk  | ijk@ijk.com | mentor        | ap chinese 2  | mno  | mno@mno.com | protege       | ap biology  communication model schema: id | userid | communicationmode | communicationdetail 1  | 1      | phone             | 1234567890 2  | 1      | email             | ijk@ijk.com  

in user model have has_many relation communication, , in communication model have belongs_to :user adding communication preferences when user sign ups application, , in setting, trying display user's communication preferences in separate controls.when user submits settings page, want delete each record in communication related current_user, working fine , code below

communication.delete_all(:userid => current_user.id) 

but when update them new action in controller, records not updating communication. , below "new" action code:

  def create     @user_basic=user.find(current_user.id)     @students=students.all     @entrepreneurs=entrepreneurs.all     @veterans=veterans.all     @user_communication=communication.where(:userid => current_user.id)     communication.delete_all(:userid => current_user.id)     @user_communication.update_attributes(:communicationmode => "communicationdetail")     render 'new'   end 

and getting below error @ line '@user_communication.update_attributes(:communicationmode => "communicationdetail")'

error: undefined method `update_attributes' 

kindly suggest me make mistake, waiting reply. thanks

i don't trying do,

@user_communication=communication.where(:userid => current_user.id) communication.delete_all(:userid => current_user.id) @user_communication.update_attributes(:communicationmode => "communicationdetail") 

you delete communications given user , try update attributes communicationmode = "communicationdetail".

so, update fails because there no record. sure there problem logic try apply.