public void ClearAllWork (int lane_id, int host_id)
{
using (IDbCommand cmd = CreateCommand ()) {
cmd.CommandText = "UPDATE Work SET state = 0, summary = '' " +
"WHERE lane_id = @lane_id " +
"AND host_id = @host_id;";
DB.CreateParameter (cmd, "lane_id", lane_id);
DB.CreateParameter (cmd, "host_id", host_id);
cmd.ExecuteNonQuery ();
}
}