ALTER TABLE leads
  ADD COLUMN referral_id VARCHAR(40) NULL AFTER id,
  ADD COLUMN invitee_id VARCHAR(40) NULL AFTER referral_id,
  ADD INDEX idx_leads_referral (referral_id),
  ADD INDEX idx_leads_invitee (invitee_id);

UPDATE leads l
JOIN referrals r
JOIN users inviter ON inviter.id = r.inviter_id
LEFT JOIN users invitee ON invitee.id = r.invitee_id
SET l.referral_id = r.id,
    l.invitee_id = r.invitee_id,
    l.parent = COALESCE(invitee.name, r.name)
WHERE l.referral_id IS NULL
  AND (
    l.parent = r.name
    OR l.parent = COALESCE(invitee.name, r.name)
    OR l.parent = CONCAT('家长', RIGHT(r.phone, 4))
  )
  AND (l.source = inviter.name OR l.source = inviter.id OR l.source = inviter.phone)
  AND (l.channel = r.channel OR l.channel = '' OR r.channel = '');