Comment by revicon

Weird, the example in the post (after changing table/field names for my database)

  with weeks as (
    select week as week
    from generate_series('2017-01-01'::date, now()::date, '1 week'::interval) weeks
  ),

  SELECT weeks.week,
    count(*)
  FROM weeks,
    test_results
  WHERE
    test_results.date_created > weeks.week
  AND
    test_results.date_created <= weeks.week - '1 week'::interval

Throws an error for me...

  ERROR:  syntax error at or near "SELECT"
  LINE 5: SELECT weeks.week,
          ^