While creating pivot report i got issue here is the my code

@api.model
def init(self):
    tools.drop_view_if_exists(self.env.cr, 'sale_last_sale_report')
    self.env.cr.execute("""            
        SELECT
        ROW_NUMBER() OVER() AS id,
        res_partner.commercial_partner_id AS partner_id

        FROM sale_order_line 
        INNER JOIN sale_order
        ON (sale_order_line.order_id = sale_order.id)
        INNER JOIN product_product
        ON (sale_order_line.product_id = product_product.id)

        GROUP BY
            res_partner.commercial_partner_id
    """)

Here is the field 

partner_id = fields.Many2one('res.partner', 'Partner', readonly=True)

Here is the pivot view in xml

    <record id="view_sale_last_sale_report_pivot" model="ir.ui.view">
        <field name="name">sale.last.sale.report.pivot</field>
        <field name="model">sale.last.sale.report</field>
        <field name="arch" type="xml">
            <pivot string="Sale Analysis" disable_linking="True">
                <field name="partner_id" type="row"/>
            </pivot>
        </field>
    </record>

I want to show partner while run code it's giving me 

error missing FROM-clause entry for table res_partner How can i fix that