Copying postgres data base with links / ref ids

Question

Trying to extract a csv of a db table

Using... COPY sale_order TO '/tmp/salesorder.csv' DELIMITER ',' CSV HEADER;

I get..

• id - partner_id
• 1 - 45
• 2 - 55

"partner_id" is references another table "contacts" as id, where I want "name"

Can I ref the partner_id to output

• id - name
• 1 -Fred Blogs
• 2 -John Smith

Answer 1

It is possible to copy from a query:

copy (
    select so.id, p.name
    from
        sale_order so
        inner join
        partner p on p.id = so.partner_id
) to '/tmp/salesorder.csv' delimiter ',' csv header;