SQL

update with join sql server

     UPDATE 
    t1
SET 
    t1.c1 = t2.c2,
    t1.c2 = expression,
    ...   
FROM 
    t1
    [INNER | LEFT] JOIN t2 ON join_predicate
WHERE 
    where_predicate;

update join sql

UPDATE 
    t1
SET 
    t1.c1 = t2.c2,
    t1.c2 = expression,
    ...   
FROM 
    t1
    [INNER | LEFT] JOIN t2 ON join_predicate
WHERE 
    where_predicate;

update join sql

MySQL:

update ud u
inner join sale s on
    u.id = s.udid
set u.assid = s.assid

----------------
SQL Server:

update u
set u.assid = s.assid
from ud u
    inner join sale s on
        u.id = s.udid
---------------
PostgreSQL:

update ud
  set assid = s.assid
from sale s 
where ud.id = s.udid;

joins in update query

update a
join b 
on a.a_id=b.b_id 
set b.is_active = 1 
where ....;