CREATE TABLE IF NOT EXISTS Labels (
  id                  INTEGER     PRIMARY KEY,
  name                TEXT        NOT NULL CHECK (name != ''),
  color               VARCHAR(7),
  custom_id           TEXT,
  account_id          INTEGER     NOT NULL,
  
  FOREIGN KEY (account_id) REFERENCES Accounts (id)
);
-- !
CREATE TABLE IF NOT EXISTS LabelsInMessages (
  label             TEXT        NOT NULL, /* Custom ID of label. */
  message           TEXT        NOT NULL, /* Custom ID of message. */
  account_id        INTEGER     NOT NULL,
  
  FOREIGN KEY (account_id) REFERENCES Accounts (id) ON DELETE CASCADE
);
-- !
UPDATE Information SET inf_value = '16' WHERE inf_key = 'schema_version';