qu.2

来自「linux 下用c++ 开发的一个小型数据库系统」· 2 代码 · 共 25 行

/*
 * test 2 tests QU_Select with 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");

/*
 * some selections involving indices
 */

/* the stars of "Days of Our Lives"*/
select real_name, plays from stars where soapid = 0;

/* names of soaps on CBS (uses secondary index) */
select name, network from soaps where network = "CBS";

/* index selection that doesn't find anything */
select name, rating from soaps where rating = 678.90;