Create a minimalist working function

Minimal state to iterate on.

SQL/plpgsql/create_add_missing_stocks.sql

@@ -0,0 +1,10 @@
+CREATE OR REPLACE FUNCTION add_missing_stocks() RETURNS void AS
+$$
+DECLARE
+    proCursor CURSOR IS SELECT pro_id FROM Product;
+    proId Product.pro_id%TYPE;
+BEGIN
+    RAISE NOTICE 'Bonjour';
+END;
+$$
+LANGUAGE plpgsql;