# Matrix expected, got Fixnum && acts\_as\_tree?

**URL:** <https://www.ruby-forum.com/t/matrix-expected-got-fixnum-acts-as-tree/114013>\
**Category:** Rails\
**Created:** [September 7, 2007, 3:30am UTC](https://www.ruby-forum.com/t/matrix-expected-got-fixnum-acts-as-tree/114013 "2007-09-07T03:30:02Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![eagoweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/9de0a6/32.png) [@eagoweb](https://www.ruby-forum.com/u/eagoweb)\
**Post date:** [September 7, 2007, 3:30am UTC](https://www.ruby-forum.com/t/matrix-expected-got-fixnum-acts-as-tree/114013/1 "2007-09-07T03:30:02Z")

</div>

Hello i got this:

class Matrix \< ActiveRecord::Base  
set\_table\_name :matrix

belongs\_to :member, :foreign\_key=\>:userid  
acts\_as\_tree :foreign\_key=\>:parent  
end

class Member \< ActiveRecord::Base  
set\_primary\_key :userid  
has\_many :matrix, :foreign\_key=\>:userid  
has\_many :matrix, :foreign\_key=\>:parent  
has\_many :payment, :foreign\_key=\>:userid  
has\_many :paymentHistory, :foreign\_key=\>:userid  
validates\_presence\_of :name  
validates\_presence\_of :identification  
validates\_presence\_of :sponsor  
end

i modeled my data like this because each member have more member through  
himself.

My problem is when i try to create a new member:  
it says: Matrix expected, got Fixnum

but if i erase the ‘acts\_as\_tree’ from matrix model it works well,  
what could be???

to save the data in my controller i got:

def create  
@member = Member.new(params[:member])  
@new\_matrix = Matrix.new  
respond\_to do |format|  
if @member.save  
@new\_matrix.userid = @member.userid  
parent = Member.find(params[:matrix]).userid  
@new\_matrix.parent = parent  
@new\_matrix.save  
flash[:notice] = ‘Member was successfully created.’  
format.html { redirect\_to member\_url(@member) }  
format.xml { head :created, :location =\> member\_url(@member) }  
else  
format.html { render :action =\> “new” }  
format.xml { render :xml =\> @member.errors.to\_xml }  
end  
end  
end

PLeased heeelp mee!  
Best Regards,