📄 段湘南.txt
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1,创建一个商品表 和 种类表;要求用到五个约束
create table commodity_1(cid number(4),cname varchar2(10),price number(7,2),kid number(4));
alter table commodity_1
add constraint pri_com_cid primary key(cid);
alter table commodity_1
add constraint check_price_1 check(price > 0);
alter table commodity_1
modify cname not null;
alter table commodity_1
add constraint uni_cname unique(cname);
create table class_1(classno number(4),classname varchar2(10));
alter table class_1
add constraint pri_cla_1 primary key(classno);
alter table commodity_1
add constraint fk_com_cid_cla_cno foreign key(cid) references class_1(classno);
alter table class_1
modify classname not null;
2,对刚才创建的商品表的列进行增,删,改操作,三个操作每个操作都有
alter table commodity_1
add produce_area varchar2(10);
alter table commodity_1
add out_date date;
alter table commodity_1
drop(out_date);
alter table commodity_1
set unused(produce_area);
alter table commodity_1
modify(cname varchar2(20));
alter table commodity_1
rename column kid to cla_id;
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