Users assigned to both variants
Ninja Van's experiment platform is supposed to assign each user to exactly one variant and keep them there. A bug in the assignment service means some users were bucketed twice, which contaminates the comparison.
From assignments, return the user_id of every user assigned to more than one distinct variant, ordered by user_id.
Schema
▸assignments
| id | SERIAL |
| user_id | INT |
| variant | TEXT |
| assigned_at | TIMESTAMP |
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