qu.7

来自「linux 下用c++ 开发的一个小型数据库系统」· 7 代码 · 共 42 行

/*
 * test 7 tests QU_Delete without indices
 */


/* 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");

print table stars;

/* Lisa is being written out of One Life to Live */
delete from stars where stars.plays = "Lisa";

/* Eugene Anthony is leaving All My Children */
delete from stars where stars.real_name = "Anthony, Eugene";

print table stars;

/*
 * General Hospital is doing poorly in the ratings this week; 
 * fire everyone 
 */
delete from stars where stars.soapid = 1;

print table stars;

/* fire everone, no matter which soap they are from */
delete from stars;

print table stars;

/*
 * ABC decides to cancel all soaps
 */
delete from soaps where soaps.network < "NBC";

print table soaps;