sql.sql

      TRUNCATE invoice_footers;
      ALTER SEQUENCE invoice_footers_id_seq RESTART WITH 1;
      ALTER TABLE invoice_footers
        ADD COLUMN page varchar;
      ALTER TABLE invoice_footers
        ADD UNIQUE (page);

      CREATE OR REPLACE FUNCTION my_function(input json)
        RETURNS json
        LANGUAGE plpgsql AS
      $func$
      DECLARE
        _key   text;
        _value text;
      BEGIN
        FOR _key, _value IN 
           SELECT * FROM json_each_text($1)
        LOOP
          INSERT INTO invoice_footers (adv_phrase, page) VALUES (_value, _key);
        END loop;

      RETURN input;

      END
      $func$;

      SELECT my_function('{"main": "", "did_service": "", "traffic_statistics": "", "capacity": "", "pstn_flat_rate_package": "", "other": ""}');
      
            CREATE OR REPLACE FUNCTION test( in_array TEXT[] ) RETURNS void AS $$
      DECLARE
          t TEXT;
      BEGIN
          FOREACH t IN ARRAY in_array LOOP
              INSERT INTO invoice_footers (adv_phrase, page) VALUES (text, page);
          END loop;
      END;
      $$ LANGUAGE plpgsql;

      SELECT test( array['a', 'b', 'c'] );