qu.3

linux 下用c++ 开发的一个小型数据库系统

/*
 * test 3 tests QU_Join
 */


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

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

select soapid,name from soaps;

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

/* another query */
select soaps.name, stars.starid from stars, soaps  where soaps.name = stars.real_name;

/*
 * a multi-step query
 */

/* names and id's of NBC stars with id's >= 9 */
select real_name, starid, soapid into temp1
from stars
where starid >= 9;

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

select real_name, starid, network
from temp2
where network = "NBC";