SQL更新table1與table2中的條件？

Question

SQL更新table1與table1中的條件？

table1:
  id_x
  field

table2:
  id
  id_x
  type_id;


update table1 set field=2 where type_id = 4;

我該怎么做（PSQL）？

Answer 1

這應該為你做的伎倆，假設id_x在表2是外鍵引用id_x table1中-

update table1 set field=2
where id_x in 
(
   select id_x from table2 where type_id = 4
)