/*第二章 作业*/create table S(    sno char(2) NOT NULL UNIQUE,    sname char(3),    city char(2));alter table S add constraint s_k primary key(sno);

create table P(    pno char(2) NOT NULL,    pname char(3),    color char(1),    weight int);alter table P add constraint p_k primary key(pno);

create table J(    jno char(2) NOT NULL,    jname char(3),    city char(2));alter table J add constraint j_k primary key(jno);

create table SPJ(    sno char(2) NOT NULL,    pno char(2) NOT NULL,    jno char(2) NOT NULL,    qty int);alter table SPJ add constraint spj_k primary key(sno,pno,jno);alter table SPJ add constraint spj_fk foreign key(sno) references s(sno);alter table SPJ add constraint spj_fk2 foreign key(pno) references p(pno);alter table SPJ add constraint spj_fk3 foreign key(jno) references J(jno);

alter table s alter column sname char(6);alter table s alter column city char(4);

insert into s values('S1', '精  益', '天津');insert into s values('S2', '万  胜', '北京');insert into s values('S3', '东  方', '北京');insert into s values('S4', '丰泰隆', '上海');insert into s values('S5', '康  健', '南京');

alter table p alter column pname char(6);alter table p alter column color char(2);

insert into p values('P1', '螺  母', '红', 12);insert into p values('P2', '螺  栓', '绿', 17);insert into p values('P3', '螺丝刀', '蓝', 14);insert into p values('P4', '螺丝刀', '红', 14);insert into p values('P5', '凸  轮', '蓝', 40);insert into p values('P6', '齿  轮', '红', 30);

alter table j alter column jname char(8);alter table j alter column city char(4);insert into j values('J1', '三    建', '北京');insert into j values('J2', '一    汽', '长春');insert into j values('J3', '弹 簧 厂', '天津');insert into j values('J4', '造 船 厂', '天津');insert into j values('J5', '机 车 厂', '唐山');insert into j values('J6', '无线电厂', '常州');insert into j values('J7', '半导体厂', '南京');

insert into spj values('S1', 'P1', 'J1', 200);insert into spj values('S1', 'P1', 'J3', 100);insert into spj values('S1', 'P1', 'J4', 700);insert into spj values('S1', 'P2', 'J2', 100);insert into spj values('S2', 'P3', 'J1', 400);insert into spj values('S2', 'P3', 'J2', 200);

insert into spj values('S2', 'P3', 'J4', 500);insert into spj values('S2', 'P3', 'J5', 400);insert into spj values('S2', 'P5', 'J1', 400);insert into spj values('S2', 'P5', 'J2', 100);insert into spj values('S3', 'P1', 'J1', 200);insert into spj values('S3', 'P3', 'J1', 200);insert into spj values('S4', 'P5', 'J1', 100);insert into spj values('S4', 'P6', 'J3', 300);insert into spj values('S4', 'P6', 'J4', 200);insert into spj values('S5', 'P2', 'J4', 100);insert into spj values('S5', 'P3', 'J1', 200);insert into spj values('S5', 'P6', 'J2', 200);insert into spj values('S5', 'P6', 'J4', 500);

/*(4)求没有使用天津供应商生产的红色零件的工程号*/select distinct jnofrom spjwhere jno not in( select jnofrom spjwhere sno in  (select snofrom swhere city='天津'and pno  in( select pnofrom pwhere color='红')));

/*(5)求至少用了S1供应商所供应的全部零件的工程号JNO */select distinct jnofrom spj xwhere  not exists    (select distinct pnofrom spj ywhere y.sno='S1' andnot exists        (select *from spj zwhere z.jno = x.jno and               z.pno = y.pno));/*首先查询SPJ表得到一个工程号的集合对于集合中的每一条记录做如下查询：取出一个工程号，比如J1 如果不存在这样的记录  查询SPJ表得到这样一个集合 --  由供应商S1供应的零件号，这里是P1, P2  1 取出一个零件号，比如pno = 'P1'    查询spj表，对于jno='J1' 并且 pno='P1'  2 取出下一个零件号，pno = 'P2'    查询spj表，对于jno='J1' 并且 pno='P2'  如果J1使用了由S1供应的零件则最后一个存在量词始终返回false  那么第一个存在量词也就始终返回false，两个存在量词都返回  false就表示该工程至少使用了S1供应商所供应的全部零件。对于一个工程，不存在这种情况，S1供应了一个零件，而该工程没有使用*/

/*（1） 统计每种零件的供应总量*/select pno, sum(qty)from spjgroup by pno

/*(2) 求零件供应总量在1000以上的供应商名字*/select s.snamefrom swhere s.sno in( select spj.sno from spj group by spj.sno having sum(qty)>1000);

insert into s values('S6', '华天', '深圳');

alter table p alter column color char(6);update pset color='粉红'where color='红';

/*(5) 将S1供应给J1的零件P1改为由P2供给*/update spjset pno='P2'where sno='S1' and jno='J1' and pno='P1';

deletefrom spjwhere pno in( select pno from p where color='蓝');