odoo v8 - Field(s) `arch` failed against a constraint: Invalid view definition

Question

I want to create a new view with a DB-view. When I try to install my app, DB-view was created then I get error:

2015-06-22 12:59:10,574 11988 ERROR odoo 
openerp.addons.base.ir.ir_ui_view: Das Feld `datum` existiert nicht

Fehler Kontext:
Ansicht `overview.tree.view`
[view_id: 1532, xml_id: k. A., model: net.time.overview, parent_id: k. A.]
2015-06-22 12:59:10,577 11988 ERROR odoo openerp.http: Exception during JSON request handling.


    ParseError: "ValidateError
    Field(s) `arch` failed against a constraint: Invalid view definition

    Error details:
    Das Feld `datum` existiert nicht

    Fehler Kontext:
    Ansicht `overview.tree.view`
    [view_id: 1532, xml_id: k. A., model: net.time.overview, parent_id: k. A.]" while parsing /opt/odoo/odoo-server/addons/net_time_overview/net_time_overview_view.xml:8, near
    <record id="net_time_overview_tree_view" model="ir.ui.view">
                    <field name="name">overview.tree.view</field>
                    <field name="model">net.time.overview</field>
                    <field name="type">tree</field>
                    <field name="arch" type="xml">              
                        <tree string="List">
                            <field name="name" readonly="1"/>
                            <field name="datum" readonly="1"/>
                        </tree>
                </field>                              
            </record>

code

from openerp import tools
from openerp.osv import fields, orm, osv

class net_time_overview (osv.osv):
    _auto = False
    _name = 'net.time.overview'
    _description = "Zeituebersicht"
    _colums = {
        'datum' : fields.date("datum", readonly=True),
        'name' :  fields.char('name', readonly=True),
        'wochentag' : fields.char('wochentag', readonly=True),
        'beschreibung' : fields.char('beschreibung', readonly=True),
        'arbeitsstd' : fields.char('arbeitsstd', readonly=True),
        'sollstd' : fields.char('sollstd', readonly=True),
        'abwesend_bez' : fields.char('abwesend_bez', readonly=True),
        'user_id':fields.many2one('res.users', 'Validation User', readonly=True),
    }

    def init(self, cr):
        tools.drop_view_if_exists(cr, 'net_time_overview')
        cr.execute("""
            CREATE OR REPLACE VIEW net_time_overview AS (
            SELECT
                (to_char(datum, 'yymmdd'))::numeric AS id,
                datum AS datum,
                res.user_id,
                res.name,
                to_char(datum, 'TMDay') AS wochentag,
... 

What's wrong in my code?

Answer 1

You have made silly mistake in defining _columns.

_colums is not valid dictionary name for fields structure. Replace this by 
_columns and restart service and update module.