CREATE TABLE topics (
    id INTEGER NOT NULL PRIMARY KEY,
    uuid char(40) NOT NULL UNIQUE DEFAULT '',
    first_update_id INTEGER NOT NULL,
    kind VARCHAR NOT NULL,
    ctime INTEGER NOT NULL,
    ctimetz INTEGER NOT NULL,
    mtime INTEGER NOT NULL,
    mtimetz INTEGER NOT NULL,
    lang VARCHAR(8) NOT NULL DEFAULT 'en',
    hash VARCHAR,
    num_updates INTEGER,
    FOREIGN KEY(first_update_id) REFERENCES updates(id) ON DELETE CASCADE
);