qu.4

linux 下用c++ 开发的一个小型数据库系统

/*
 * test 4 has more QU_Join stuff
 */


/* create the relations and indices */
create table soaps(soapid int, name char(28), network char(4), rating real);
/*
buildindex soaps(name);
buildindex soaps(network);
*/
load table soaps from ("../data/soaps.data");

create table stars(starid int, real_name char(20), plays char(12), soapid int);
/*
buildindex stars(plays);
buildindex stars(soapid);
*/
load table stars from ("../data/stars.data");


/*
 * more joins
 */

/* print names of stars and the soaps they star in */
select stars.plays, soaps.name, soaps.network from stars, soaps where stars.soapid = soaps.soapid;

/* names and id's of stars of soaps having rating < 4.6 with starid's < 7 */
select real_name, starid, soapid into temp1 
from stars
where starid < 7;

select temp1.real_name, temp1.starid, soaps.rating into temp2 
from temp1,soaps
where temp1.soapid = soaps.soapid;

select real_name, starid, rating from temp2 where rating < 4.6;