《数据库系统概论》第五版第三章课后题4

--求供应工程J1零件的供应商号码SNO
select distinct SNO
from SPJ 
where JNO='J1'

--求供应工程J1零件P1的供应商号码SNO
select SNO
from SPJ 
where JNO='J1' and PNO='P1'

--求供应工程J1零件为红色的供应商号码SNO
select SNO
from P,SPJ
where P.PNO=SPJ.PNO and JNO='J1' and COLOR='红'

select SNO
from SPJ
where JNO='J1' and PNO in
(
    select PNO
    from P
    where COLOR='红'
)

select SNO
from SPJ
where JNO='J1' and  exists   --相干子查询
(
    select *
    from P
    where COLOR='红' and P.PNO=SPJ.PNO
)

--求没有使用天津供应商生产的红色零件的工程号JNO

select JNO
from J
where JNO not in
(
    select JNO
    from S,P,SPJ
    where CITY='天津' and COLOR='红' and S.SNO=SPJ.SNO and P.PNO=SPJ.PNO
)

select JNO
from J
where JNO <>all
(
    select JNO
    from S,P,SPJ
    where CITY='天津' and COLOR='红' and S.SNO=SPJ.SNO and P.PNO=SPJ.PNO
)

select JNO
from J
where JNO !=all
(
    select JNO
    from S,P,SPJ
    where CITY='天津' and COLOR='红' and S.SNO=SPJ.SNO and P.PNO=SPJ.PNO
)

select JNO
from J
where not exists
(
    select *
    from S,P,SPJ
    where CITY='天津' and COLOR='红' and S.SNO=SPJ.SNO and P.PNO=SPJ.PNO and SPJ.JNO=J.JNO
)

select JNO
from J
except
select JNO
from S,P,SPJ
where CITY='天津' and COLOR='红' and S.SNO=SPJ.SNO and P.PNO=SPJ.PNO

--求至少使用了供应商S1所供应的全部零件的工程号JNO
select distinct JNO
from SPJ  x
where not exists
(
    select *
    from SPJ y
    where SNO='S1' and not exists 
    (
        select *
        from SPJ z
        where JNO=x.JNO and PNO=y.PNO
    )
)