Hello Ahmed,

_coloumn spell is wrong.

Try this :-

Old api :-

from openerp import models,fields, osv

class book(models.Model):

    _name="book.book"

    _description="simple book"

    _columns = {

        'title' : fields.char(string='Title', required=True),

        'desc': fields.text("Description"),

        'author': fields.char(string="Author", size=30, required=True),

    }

New Api :-

from openerp import models,fields, osv

class book(models.Model):

    _name="book.book"

    _description="simple book" 

    title =  fields.Char(string='Title', required=True)

    desc = fields.Text("Description")

    author =  fields.Char(string="Author", size=30, required=True)

Hope this useful to you.

Thanks,