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SQL Duplicate Consumer Profiles
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SQL Duplicate Consumer Profiles

MediumSQL · PostgreSQL

Problem

Write a SQL query to identify duplicate consumer profiles based on partial name and location matches.

Normalize names by ignoring case and non alphabetic characters. Profiles with NULL name components or a NULL location_id must be ignored.

Output

  1. One row per matching profile pair, with profile_id_1, profile_id_2, profile_name_1, profile_name_2, city, and state.
  2. Include each pair once, with the lower profile ID first.
  3. Order by profile_id_1, then profile_id_2.

Schema

consumer_profiles
ColumnTypeDescription
profile_idPKINTEGERUnique consumer profile identifier
first_nameVARCHAR(100)Consumer first name
last_nameVARCHAR(100)Consumer last name
location_idINTEGERReference to the consumer location
locations
ColumnTypeDescription
location_idPKINTEGERUnique location identifier
cityVARCHAR(100)City name
stateVARCHAR(2)Two-letter state code
Tablesconsumer_profileslocations
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