Skip to main content

Resolving Duplicate User Email Addresses

Artemis is preparing to enforce one case-insensitively unique email address per user account. During the preparation phase, Artemis rejects new conflicts and sends a weekly warning to info.contact when legacy conflicts remain. A future release will add the database constraint and will not start until all conflicts are resolved.

The warning email intentionally contains only numeric user IDs. Names, logins, and email addresses must be inspected locally to limit personal data in email systems.

Find affected accounts​

MySQL:

SELECT LOWER(email) AS normalized_email,
       COUNT(*) AS account_count,
       GROUP_CONCAT(id ORDER BY id) AS user_ids,
       GROUP_CONCAT(login ORDER BY id SEPARATOR ', ') AS logins
FROM jhi_user
WHERE email IS NOT NULL AND TRIM(email) <> ''
GROUP BY LOWER(email)
HAVING COUNT(*) > 1
ORDER BY account_count DESC, normalized_email;

PostgreSQL:

SELECT LOWER(email) AS normalized_email,
       COUNT(*) AS account_count,
       STRING_AGG(id::text, ',' ORDER BY id) AS user_ids,
       STRING_AGG(login, ', ' ORDER BY id) AS logins
FROM jhi_user
WHERE email IS NOT NULL AND BTRIM(email) <> ''
GROUP BY LOWER(email)
HAVING COUNT(*) > 1
ORDER BY account_count DESC, normalized_email;

Resolve each conflict​

Review each group rather than selecting an account automatically. Artemis does not provide a general-purpose account merge: submissions, grades, course memberships, and permissions must not be reassigned based only on matching email addresses.

  • For an obsolete account, deactivate it and set its email to NULL. This preserves references to the user while releasing the address.
  • For distinct active people, obtain separate personal addresses. Do not use fabricated addresses because Artemis could send confidential notifications to them.
  • For two accounts belonging to the same person, choose the account that should remain active. Preserve the other account until its academic data and permissions have been reviewed; clear its email rather than deleting it.
  • Treat addresses that differ only by letter case as duplicates.

Example after reviewing the selected account IDs:

START TRANSACTION;

UPDATE jhi_user
SET email = NULL,
    activated = FALSE
WHERE id IN (
    -- reviewed obsolete account IDs
);

-- Run the detection query again before committing.
COMMIT;

Back up the database and follow the institution's account-retention and audit policies before changing production data.

SAML2 and Shibboleth installations​

Artemis identifies a SAML2 user by the login produced by saml2.username-pattern; it does not link accounts by email. The asserted email is contact data and must be unique when present. This prevents a new or changed federated identity from being attached to an existing account merely because the IdP returned the same mailbox.

Configure saml2.username-pattern from a stable, persistent, and globally unique IdP attribute. A scoped identifier such as eduPersonPrincipalName, subject-id, or another institution-controlled immutable identifier is preferable. Do not derive usernames from first and last names. With multiple IdPs, ensure the resulting usernames cannot overlap across providers.

Before enabling the future constraint, check these IdP cases:

  • If an IdP identifier changed for the same person, update the existing Artemis login through user administration or restore the stable IdP identifier. Do not allow the next login to create a second Artemis account.
  • If an email was recycled for a different person, remove or replace it on the former Artemis account before provisioning the new person.
  • If distinct federated identities intentionally share a mailbox, provide unique personal addresses or omit the email attribute for accounts that do not require email-based workflows. Blank SAML2 email attributes are stored as NULL during the preparation phase.
  • If multiple IdPs are configured, coordinate identifier and email ownership across all of them. Artemis currently records an account as external but does not persist which IdP created it, so provider attribution must be established from the IdP and operational records.

New SAML2, OIDC, and LDAP accounts whose asserted email is already assigned are rejected during provisioning. Existing externally managed accounts remain usable while their legacy conflicts are reviewed, provided the external directory does not attempt to change their email to a conflicting value.

Internal admin account​

artemis.user-management.internal-admin.email is one fixed address and defaults to a placeholder, so it can already belong to another account, for example a previous internal admin that was renamed. When Artemis has to create the internal admin and finds the configured address taken, it creates the account without an email address and logs a warning naming the setting. Point the setting at an unused address if the internal admin needs one, for instance to receive the password reset email.

Verify readiness​

The installation is ready for the implementation phase when the detection query returns no rows. Keep the weekly report enabled until the release containing the database constraint has been deployed successfully.

Search documentation