I made a simple model called "Movie", and defined a function to create a new record

class Movie(models.Model):    _name = 'cinema.movie'​

    name = fields.Char(string='Name',required=True)
    category = fields.Char(string='Category',required=True)

def create_movie(self):
        movie1 = {
                 'name': 'Movie A',
                 'category': 'Action film'
                 }
                 self.env['cinema.movie'].create(movie1)

Then I add a button in the tree view of the model. When I create the first record, a button appears after the field of category, and it works when I click on it

<button string="Create Movie" type="object" name="create_movie"/>

However, when I try to trigger the code by a menu item, it doesn't work

<record id="action_create_movie" model="ir.actions.server">
   <field name="name">Create Movie</field>
   <field name="type">ir.actions.server</field>
   <field name="model_id" ref="model_cinema_movie"/>
   <field name="state">code</field>
   <field name="code">model.create_movie</field>
</record>

I'm very new to python and odoo. I sort of feel it might be resulted by the difference of a class and instance, but I really don't know how to fix this. Can anybody help me? Maybe just give  some keywords and I could google it. 

Thanks.