We're sending anniversary mails to members every time they've lasted another year with us :)
This is the SOQL *appending* data to the Data Extension [Anniversary Flow - Trigger]

    SELECT
    ID as 'Subscriber Key',
    CreatedDate,
    CASE WHEN Email IS NULL THEN '[email protected]'
    ELSE EMAIL
    END AS EMAIL,
    Country,
    Segmentation,
    locale,
    DATEPART(year, GETDATE()) - DATEPART(year, CreatedDate) as 'Anniversary years'
    From Subscribers
    WHERE DATEPART(day, DATEADD(HOUR, 7, GETDATE())) = DATEPART(day, CreatedDate) AND
    DATEPART(month, GETDATE()) = DATEPART(month, CreatedDate) 
    AND (DATEPART(year, GETDATE()) - DATEPART(year, CreatedDate)) > 0

This has worked perfectly until now.
The Data Extension has 2 primary keys:
Subscriber Key
Anniversary years

We've recently had an example of a subscriber having the CreatedDate renewed, causing the automation *appending* data to the Data Extension [Anniversary Flow - Trigger] to error with a 'Violation of PRIMARY KEY constraint' as that member was now starting all over on her anniversary years and for that reason already existed in the Data Extension.

**How can I alter the SOQL above to not include subscribers if they're already existing in the [Anniversary Flow - Trigger] with that combination of primary keys**

And yes, I'm aware that this is not solving all my problems, but it'd be really helpful here and now and a perfect temporary solution.

Thank you