inside py
@api.model
def run_sql(self, qry):
self._cr.execute(qry)
_res = self._cr.fetchall()
return _res

qweb

<t t-set= "amount" t-value="o.id" ></t>
<t t-foreach="docs" t-as="o">
<t t-set="latest_partner" t-value="o.run_sql('SELECT  DISTINCT  purchase_request.Name as MaterialRequest,purchase_request.origin as Source Fromm  purchase_request INNER  JOIN purchase_request_line  on purchase_request_line.request_id = purchase_request.id
INNER  JOIN purchase_order_purchase_request_line_rel on purchase_order_purchase_request_line_rel.purchase_request_line_id = purchase_request_line.id
where
purchase_order_purchase_request_line_rel.purchase_order_id =%s' % amount)"/>
<span t-esc="latest_partner"/>
<span t-esc="part"/>  </t> </t>