thanks  for your reply,Allen!
     the problems are as follow:
     The main code is:


 ----------
if( -1 == mme_play( mme, 0) ) {
			perror( "mme_play()" );
		} else {
			printf( "mme_play(): success\n" );
		
		}	
		
		mme_trksessionview_update(mme);
		mme_play_get_info(mme,&info) ;
		

		if( -1==qdb_statement(qdb,"SELECT filename, artist, album, genre, composer"
				" FROM nowplaying"))
		perror( "qdb_statement()");
		else {

			printf( "qdb_statement(): success\n" );		}

		
	

		res = qdb_getresult(qdb);
		columns=qdb_columns(res);
		rows=qdb_rows(res);
		printf( "\n" );
		printf( "rows is %d",rows );
		printf( "\n" );
		printf( "columns is %d",columns );
		printf( "\n" );
		strcpy(file_name,qdb_cell(res, 0, 0));
		//strcpy(album,qdb_cell(res, 0, 1));
		strcpy(artist,qdb_cell(res,0,1));
		qdb_freeresult( res );
#ifdef DEBUG
		printf("The file name is %s\n",file_name);
		printf("The  artist is %s\n",artist);
		//	printf("The album is %s\n",album);
#endif 



When I run the application,the result of print is :


mme_device /dev/mme/default
Connected to '/dev/mme/default'
trk session created: id = 11
mme_setrandom( MME_RANDOM_OFF )
Normal mme_play(): success
qdb_statement(): success

rows is 1
columns is 5
The file name is Can You Feel the Love Tonight.mp3
The  artist is Unknown Artist


I can not get the artist from the nowplaying,please give me the idle,thanks!