Hi 

I am trying to get a related field value from database, but it showing column 'column_name' does not exist. 

When i try to find out the value of product_id or using join to find the common data between sale.order and product.product Model . but it showing column 'column_name' does not exist.

In sale.order model the field defination is like 

product_id = fields.Many2one('product.product', related='order_line.product_id', string='Product')

But when i try to join two table like below code to fetch all data as per product, like below code.

select coalesce(p.name,'Unassigned Product'), count(*) from sale_order o left join product_product p on o.product_id = p.id where o.state = 'sale' group by p.name;

It showing below error, 

column o.product_id does not exist
LINE 1: ... from sale_order o left join product_product p on o.product_...

When i try to get data from sale_order  table like below code.

select product_id from sale_order; 

It showing below error. 

column "product_id" does not exist

Can any one help me to get that value.