经过几天的SQL培训，我终于找到了一个解决方案，我把它贴在这里，它可能会帮助一些人，特别感谢@S-Man的激励：）

DO
    $$
    DECLARE
      sql text;
    BEGIN
      WITH latest_create_date AS (
        SELECT product_code, week, MAX(create_date) AS max_create_date
        FROM my_table_name
        WHERE related_id = 437
        GROUP BY product_code, week
      )
      SELECT string_agg(
        DISTINCT 'SUM(CASE WHEN rop.week = ' || CAST(rop.week AS text) ||
                 ' THEN rop.qty ELSE 0 END) AS ' || rop.week || '',
        ', '
      ) INTO sql
      FROM my_table_name rop
      INNER JOIN latest_create_date lcd
      ON rop.product_code = lcd.product_code AND rop.week = lcd.week AND rop.create_date = lcd.max_create_date;
    
      IF sql IS NOT NULL THEN
        sql := 'SELECT product_code, ' || sql ||
               ' FROM my_table_name WHERE related_id = 437 GROUP BY product_code';
    
        EXECUTE sql;
      END IF;
    END;
    $$ LANGUAGE plpgsql;