CREATE TABLE token_entity (
  user_id TEXT PRIMARY KEY,
  token TEXT NOT NULL
);

selectTokenByUserId:
SELECT token
FROM token_entity
WHERE user_id = ?
LIMIT 1;

insertToken:
INSERT INTO token_entity(user_id, token)
VALUES (?, ?)
ON CONFLICT(user_id) DO
UPDATE SET user_id=excluded.user_id, token=excluded.token;
