For loop postgreSQL doesn't seem to work properly

Question

I'm currently in the process of doing a huge manual work which I could solve with a simple for loop.

Here is my query :

FOR i IN 317..349 LOOP
   update ville
   set ville.id_de = i from ville, departement where ville.nom_dep_vi = departement.nom_de AND i = departement.id_de;
END LOOP;

Here is the official PostgreSQL's syntax:

FOR i IN 1..10 LOOP
-- i will take on the values 1,2,3,4,5,6,7,8,9,10 within the loop
END LOOP;

I always get an error saying "Query failed PostgreSQL said: syntax error at or near "i"". If anyone could help that'd be appreciated.

Answer 1

No need for a loop, just use a single update statement:

update ville
  set ville.id_de = departement.id_de
from departement -- do NOT repeat ville here!
where ville.nom_dep_vi = departement.nom_de 
  AND departement.id_de between 317 and 349