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Identify Pre-Upgrade Touchpoint
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Identify Pre-Upgrade Touchpoint

MediumSQL · PostgreSQL

Problem

How would you write a query to identify the touchpoint that occurred immediately prior to a user upgrading to a paid plan at Retool?

Use the provided Retool users, touchpoints, and plan upgrades data. Return only upgrades with at least one earlier touchpoint, selecting the latest prior event and resolving timestamp ties by the highest touchpoint ID.

Output

  1. One row per qualifying paid-plan upgrade
  2. Columns: upgrade_id, user_id, upgraded_at, touchpoint_id, touchpoint_type, touchpoint_at
  3. Order by upgrade_id ascending

Schema

users
ColumnTypeDescription
user_idPKINTRetool user identifier
user_nameVARCHAR(100)User display name
touchpoints
ColumnTypeDescription
touchpoint_idPKINTTouchpoint identifier
user_idINTUser associated with the touchpoint
touchpoint_typeVARCHAR(50)Marketing or product interaction type
occurred_atTIMESTAMPTimestamp when the touchpoint occurred
plan_upgrades
ColumnTypeDescription
upgrade_idPKINTPaid-plan upgrade identifier
user_idINTUser who upgraded
upgraded_atTIMESTAMPTimestamp when the user upgraded
Tablesuserstouchpointsplan_upgrades
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