我有一个表表示与另一个表中的单个行相关的一组值.我可以通过删除所有值并添加新集合,或者通过有选择地删除某些值并添加其他值来更改这些值,但是如果可能,我有兴趣将其设置为单个语句.

这是一个更新的工作示例.为了使这项工作,我不得不添加虚拟,以便一列可用于更新,不是在条件.有没有办法只删除和插入没有一个虚拟列来更新？

即使没有实际更新,也不能在更新设置列表中显示条件的列.

create table every_value ( the_value varchar2(32) );
create table paired_value ( the_id number,a_value varchar2(32),dummy number default 0 );
-- the_id is a foreign_key to a row in another table

insert into every_value ( the_value ) values ( 'aaa' );
insert into every_value ( the_value ) values ( 'abc' );
insert into every_value ( the_value ) values ( 'ace' );
insert into every_value ( the_value ) values ( 'adg' );
insert into every_value ( the_value ) values ( 'aei' );
insert into every_value ( the_value ) values ( 'afk' );

-- pair ace and afk with id 3
merge into paired_value p using every_value e
on ( p.the_id = 3 and p.a_value = e.the_value )
when matched then update set dummy=dummy+1
delete where a_value not in ('ace','afk')
when not matched then insert (the_id,a_value)
values (3,e.the_value)
where e.the_value in ('ace','afk');

-- pair ace and aei with id 3
-- should remove afk,add aei,do nothing with ace
merge into paired_value p using every_value e
on ( p.the_id = 3 and p.a_value = e.the_value )
when matched then update set dummy = dummy+1
delete where a_value not in ('ace','aei')
when not matched then insert (the_id,'aei');

-- pair aaa and adg with id 4
merge into paired_value p using every_value e
on ( p.the_id = 4 and p.a_value = e.the_value )
when matched then update set dummy = dummy+1
delete where a_value not in ('aaa','adg')
when not matched then insert (the_id,a_value)
values (4,e.the_value)
where e.the_value in ('aaa','adg');

select * from paired_value;

我已经在oracle 10g中试过了,而这个sqlfiddle,oracle 11g.