How can I combine results from different expression?

Grafana Alerting
,
1

I have a postgresql database that stored 3 column. Time, value, feed_id. Feed_id column will serve as label. My goal is to alert feed_id that has data within last 30 days but no data within last 24 hours. How can I achieve this?

Qyery A: Now-30d

SELECT
  time AS time,
  value,
  CASE
    WHEN fid = 1040978 THEN '104'
    WHEN fid = 1040910 THEN '158'
    WHEN fid = 1040909 THEN '160'
    WHEN fid = 1040903 THEN '161'
    WHEN fid = 1040904 THEN '151'
    WHEN fid = 1041102 THEN '113'
    WHEN fid = 1124443 THEN '162'
    WHEN fid = 1125512 THEN '163'
    WHEN fid = 1125507 THEN '159'
    WHEN fid = 1124470 THEN '183'
  END AS dataset
FROM
  feed_obs
WHERE
  $__timeFilter(time)
  AND fid IN (
    1040978,
    1040910,
    1040909,
    1040903,
    1040904,
    1041102,
    1124443,
    1125512,
    1125507,
    1124470
  )
ORDER BY
  1

Qyery B: Now-1d

Same query as above

Expression:

image
image2270×818 85.5 KB

In this case, I want all labels shown alert is firing except dataset=158, 160 and 161

I use count. Maybe combine last with bool expression work? This might not be an elegant way to achieve. Can anyone give some help? Thanks a lot!