sfmc // SQLPRODUCTION

First Unique Open in a Window

Return the first unique open date per subscriber within a defined analysis window.

sqlopenisuniquemin

Trust & provenancePRODUCTION

Evidence tierPRODUCTIONOfficial sources0Other sources0Last verified2026-10-05

Evidence tier describes my hands-on relationship with the content. Official sources describe platform contracts/documentation. Production observations should not automatically be treated as official limits.

EvidencePRODUCTION

Difficultyfoundation

Verified2026-10-05

Use when

Building engagement recency or lifecycle metrics.

SELECT
    SubscriberKey,
    MIN(EventDate) AS FirstOpenDate
FROM _Open
WHERE IsUnique = 1
  AND EventDate >= DATEADD(day,-30,GETDATE())
GROUP BY SubscriberKey

Why it works

IsUnique reduces repeated opens at the tracking-event level and MIN selects the earliest qualifying event in the requested window.

Operational notes

Define whether uniqueness should be interpreted per job/event or across your final reporting grain.

Latest Unique Click per Subscriber

Collapse click tracking to one latest engagement timestamp per subscriber.

→

First Unique Open in a Window

Keep following the context.