Although CiviCRM community recommends not to manipulate the database directly, these queries are useful for deleting duplicate emails, phones and addresses within the contact

Delete duplicate emails

DELETE civicrm_email.* FROM civicrm_email LEFT JOIN( SELECT MIN(id) min_id FROM civicrm_email e JOIN (SELECT contact_id, email FROM civicrm_email GROUP BY contact_id, email) AS f ON f.email = e.email AND f.contact_id = e.contact_id GROUP BY e.email, e.contact_id) ids ON civicrm_email.id = ids.min_id WHERE ids.min_id IS NULL AND civicrm_email.contact_id IS NOT NULL

Delete duplicate phones

DELETE civicrm_phone.* FROM civicrm_phone LEFT JOIN( SELECT MIN(id) min_id FROM civicrm_phone e JOIN (SELECT contact_id, phone FROM civicrm_phone GROUP BY contact_id, phone) AS f ON f.phone = e.phone AND f.contact_id = e.contact_id GROUP BY e.phone, e.contact_id) ids ON civicrm_phone.id = ids.min_id WHERE ids.min_id IS NULL AND civicrm_phone.contact_id IS NOT NULL

Delete duplicate addresses

DELETE civicrm_address.* FROM civicrm_address LEFT JOIN( SELECT MIN(id) min_id FROM civicrm_address e JOIN (SELECT contact_id, street_address FROM civicrm_address GROUP BY contact_id, street_address) AS f ON f.street_address = e.street_address AND f.contact_id = e.contact_id GROUP BY e.street_address, e.contact_id) ids ON civicrm_address.id = ids.min_id WHERE ids.min_id IS NULL AND civicrm_address.contact_id IS NOT NULL AND civicrm_address.street_address <> ''
Set a primary email:

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