-- several users per client account: invitations, and a separate address for invoices
CREATE TABLE client_invites (
  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  client_id INT UNSIGNED NOT NULL,
  email VARCHAR(190) NOT NULL,
  permissions VARCHAR(500) NOT NULL DEFAULT '',
  token_hash CHAR(64) NOT NULL,
  invited_by INT UNSIGNED NULL,
  created_at DATETIME NOT NULL,
  expires_at DATETIME NOT NULL,
  accepted_at DATETIME NULL,
  UNIQUE KEY token (token_hash),
  KEY client (client_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
ALTER TABLE clients ADD billing_email VARCHAR(190) NOT NULL DEFAULT '' AFTER email;