问Postgres如何分解导入不同模式的问题，需要将类别数组“散开”到类别表中

EN

CREATE TABLE public.categories ( 
    id SERIAL PRIMARY KEY NOT NULL,
    parent Integer,
    category Text NOT NULL UNIQUE
);

CREATE TABLE public.companies_categories ( 
    id SERIAL PRIMARY KEY NOT NULL,
    category_id Integer NOT NULL,
    company_id Integer NOT NULL
);

create or replace function scan_categories()
returns setof categories as $$ 
declare
   category_list varchar[];
   category_text varchar;
   category_id int;
   company_id int;
BEGIN

FOR category_list, company_id IN SELECT categories, id FROM public.companies
  LOOP
    IF category_list IS NOT NULL
    THEN
        FOREACH category_text IN ARRAY category_list
            LOOP
               INSERT INTO public.categories(category) VALUES (category_text) ON CONFLICT DO NOTHING;
               SELECT id FROM public.categories INTO category_id WHERE category LIKE category_text;
               INSERT INTO companies_categories (category_id, company_id) VALUES (category_id, company_id);
            END LOOP;
    END IF;
  END LOOP;
END
$$