CREATE TABLE instances (
    id INTEGER PRIMARY KEY NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL,
    domain_name TEXT NOT NULL COLLATE NOCASE UNIQUE,
    json TEXT,
    blocked BOOLEAN NOT NULL DEFAULT 0,
    last_message_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL
);

CREATE TRIGGER instances_updated_at
    AFTER UPDATE ON instances FOR EACH ROW
    WHEN OLD.updated_at = NEW.updated_at OR OLD.updated_at IS NULL
BEGIN
    UPDATE instances SET updated_at=CURRENT_TIMESTAMP WHERE id=NEW.id;
END;