假设我有以下表结构:
a (a_id number primary key, a_code varchar unique not null)
b (b_id number primary key, a_id number foreign key references a(a_id), b_value varchar
如果它们尚不存在,我需要在表上插入b
几百对,并且我拥有的信息是. 我来自 Postgres 背景,这样做是微不足道的,但我很难找到一种在 Oracle 中实现它的方法,而无需求助于创建并随后删除物化视图,或者每行插入一个。(a_id, b_value)
(a_code, b_value)
这是我能想出的最不难看的解决方案:
insert /*+ IGNORE_ROW_ON_DUPKEY_INDEX(b_value, iun_b_value) */
into b (b_id, a_id, b_value)
select b_id.nextval, a_id, b_value
from a
inner join
(select 'code1' a_code, 'value1' b_value from dual union all
select 'code2' a_code, 'value2' b_value from dual union all
select 'code3' a_code, 'value3' b_value from dual union all
select 'code4' a_code, 'value4' b_value from dual) new
on a.a_code = new.b_value
但是我被告知我不能使用该语义提示来处理生产中的重复行,所以我尝试了这个:
merge into b using
(select a_id, b_value
from a inner join
(select 'code1' a_code, 'value1' b_value from dual union all
select 'code2' a_code, 'value2' b_value from dual union all
select 'code3' a_code, 'value3' b_value from dual union all
select 'code4' a_code, 'value4' b_value from dual) new
new on a.a_code = new.a_code) insert_codes
on (insert_codes.a_code = b.a_code and insert_codes.b_value = b.b_value)
when not matched then
insert (b.b_id, b.a_id, b.b_value)
values (b_id.nextval, insert_codes.a_id, 1, insert_codes.b_value)
但是当我尝试使用子句"ORA-00980: synonym translation is no longer valid"
解决此问题时,我在子选择中引用别名时遇到了同样的错误。where not exists
有没有办法在没有物化视图或多个插入的情况下做到这一点?