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每两周的优胜者可获得itpub奖励的技术图书一本。
以往旧题索引:
http://www.itpub.net/forum.php?m ... eid&typeid=1808
原始出处:
http://www.plsqlchallenge.com/
作者:Chris Saxon
运行环境:SQLPLUS, SERVEROUTPUT已打开, 最低版本要求:11.2
注:本题给出答案时候要求给予简要说明才能得到奖品
你执行了这些命令:
create table qz_bricks (
brick_id integer
not null
primary key,
colour varchar2(10)
not null,
shape varchar2(10)
not null
);
insert into qz_bricks
values ( 1, 'red', 'cylinder' );
insert into qz_bricks
values ( 2, 'red', 'cube' );
insert into qz_bricks
values ( 3, 'blue', 'cylinder' );
insert into qz_bricks
values ( 4, 'blue', 'cube' );
insert into qz_bricks
values ( 5, 'green', 'cylinder' );
insert into qz_bricks
values ( 6, 'green', 'cube' );
commit;
哪些选项会返回这些数据,每种颜色一行?
COLOUR
----------
blue
green
red
(A)
select colour
from qz_bricks
orderby colour;
(B)
select distinct colour
from qz_bricks
orderby colour;
(C)
select unique colour
from qz_bricks
orderby colour;
(D)
select colour
from qz_bricks
groupby colour
orderby colour;
(E)
select max ( colour ) colour
from qz_bricks
groupby shape
orderby colour;
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