hardGXBank · windowBasicNew
Show each customer's previous tier alongside their new one
The plan_changes table logs every tier change per customer, in order. For each row, return customer, changed_at, new_tier, and previous_tier — the tier the customer was on immediately before this change.
A customer's very first logged change should show previous_tier as NULL.
Schema
▸plan_changes
| id | INT |
| customer | TEXT |
| changed_at | DATE |
| new_tier | TEXT |
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