Why do these two queries return different results?

Question

I have a requirement to get the most recent task date on an account. When I use the following query, Salesforce does not return the correct answer. If I do the same query but on the task object, the result is correct.

SELECT ...
(
    SELECT Id, ActivityDate, AccountId, WhatId, WhoId From Tasks
    Where SalesLoft1__Call_Disposition__c = null
    and (Not subject Like '%aircall%')
    and (Not subject Like '%Marketing%')
    and ActivityDate != null order by ActivityDate desc
) from Account where Id = '0015q000006T3y3AAC'

The result from this gives me an older task

When I query from the Task object, I get the correct task. Why would there be different results for the same account?

SELECT Id, subject, ActivityDate, AccountId, WhatId, WhoId From Task
Where accountid = '0015q000006T3y3AAC'
and SalesLoft1__Call_Disposition__c = null
and (Not subject Like '%aircall%')
and (Not subject Like '%Marketing%')
and ActivityDate != null order by ActivityDate desc Limit 1

Any ideas?

Answer 1

The Tasks relationship is tied to the WhatId field. If you look closer, you'll see in the first screenshot that WhatId is populated with the Account Id, while in the second query, you'll see that WhatId is null (not populated). In other words, the second query is returning a task that is indirectly related to the Account (e.g. a Contact or Opportunity), but is not directly related to the Account. I'll leave it up to you to decide which task you really meant to retrieve, as they are two different concepts.

Answer 2

You can get the result by appending a clause called MRU. However, you cannot use additional filters with it.

I have used your query but I guess you want the reverse of it. The thing is you can either query recent accounts or tasks. may be not both... However MRU works

MRU means MOST RECENTLY USED I guess