class DBRevision:

    def __init__(self, row):
        (self.dbid, self.project, self.package, self.rev, self.unexpanded_srcmd5, self.commit_time, self.userid, self.comment, self.requestid) = row

    @classmethod
    def fetch_revision(cls, db, project, package, rev):
        cur = db.cursor()
        cur.execute("SELECT * FROM revisions where project=%s and package=%s and rev=%s", (project, package, rev))
        row = cur.fetchone()
        cur.close()
        return DBRevision(row)

    @classmethod
    def latest_revision(cls, db, project, package):
        cur = db.cursor()
        cur.execute("SELECT MAX(rev) FROM revisions where project=%s and package=%s", (project, package))
        max = cur.fetchone()[0]
        cur.close()
        if max:
            return DBRevision.fetch_revision(db, project, package, int(max))
        return None