Question

I’m trying to write a query to find an eligble key. The criteria for an key being eligble is that it must not have been used 10 times within 24 hrs.

Every time a key has been used, a record is saved in my table api_history.

Can anyone please teach me how to do it correctly? Currently I’m getting an empty key returned, as no records exists in the api_history. (Then it should just have returned the first giving key).

Thanks in advance!

Query:

SELECT ak.key 
FROM api_history ah 
  INNER JOIN api_keys ak ON ah.key_id = ah.id 
WHERE ah.used_at > DATE_SUB(now(), INTERVAL 1 DAY) 
HAVING COUNT(ah.id) < 10 LIMIT 0,1

Tables:

api_keys

• id (int)
• key (string)

api_history

• id (int)
• key_id (int)
• used_at (datetime)

Answer 1

Will it work for you?

SELECT ak.key, COUNT(ah.id) as num_usage_24hrs 
FROM api_keys  ak
LEFT JOIN api_history ah ON (ah.key_id = ak.id 
    AND ah.used_at > DATE_SUB(now(), INTERVAL 1 DAY) )    
GROUP BY ak.key
HAVING COUNT(ah.id) < 10 

** you probably don’t need COUNT(ah.id) as num_usage_24hrs in select, I output it just for debugging.

UPDATED (It should be ah.key_id = ak.id, not ah.key_id = ah.id )