-- Unread messages tracking
CREATE TABLE IF NOT EXISTS channel_reads (
    user_id INT NOT NULL,
    channel_id INT NOT NULL,
    last_read_message_id INT NOT NULL,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    PRIMARY KEY (user_id, channel_id),
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (channel_id) REFERENCES channels(id) ON DELETE CASCADE
);