sql - Postgres Update multiple rows -

i need update multiple rows in table.

i have table customer , contact

i need update customer linked contact in contact table has column city @ value. can rows need query

select cus.id, con.city  customer cus, contact con  cus.contacts_id=con.id    , con.city="myvalue"

i know how update 1 table not understand how update table when rows looked different table.

firstly, please not use old joins (from comma separated tables).

secondly, here go:

update customer set whatever = 'whatever value' contacts_id in (     select id contact city="myvalue" )

Today