FMResultSet *result = [self.sqldb selectChatRoom];
    self.chatRoom = [[NSMutableArray alloc] init];
    while ([result next]) {
        ChatRoom *chatRoom = [[ChatRoom alloc] init];
        chatRoom.chatRoomChat = [result stringForColumn:@"chatRoomChat"];
        chatRoom.chatRoomTitle = [result stringForColumn:@"chatRoomTitle"];
        chatRoom.chatRoomId = [result intForColumn:@"chatRoomId"];
        [self.chatRoom addObject:chatRoom];
    }

+ (SQLDB *) shared {
    static SQLDB *instance = nil;
    static dispatch_once_t pred;
    
    dispatch_once(&pred, ^{
        instance = [[SQLDB alloc] init];
    });
    return instance;
}