is it possible to do an update with a nested select that references the outer update ?

A typo in a webapp left ~150 records damaged overnight

I was hoping to automate this, but may just use regex to make update
statements for this

basically , i have this situation:

table a ( main record )
id , id_field , fullname

table b ( extended profiles )
id_field , last_name , first_name, middle_name , age , etc

id_field on table a was left null due to a typo with the orm

i've tried many variations to automate it, none seem to work

i think this attempt most clearly expresses what I was trying to do

UPDATE table_a a set id_field = ( SELECT id_field FROM table_b b
WHERE a.first_name || ' ' || b.last_name = a.fullname ) WHERE id_field
IS NULL ;

I'd be greatful if anyone has a pointer