[英]Oracle SQL query joining same table
我有一張這樣的桌子:
items
id old_new object
1 o pen
2 n house
3 o dog
4 o cat
5 n carrot
我想要選擇返回:
id new_object old_object
1 null pen
2 house null
3 null dog
4 null cat
5 carrot null
我是否需要在同一張表上使用外部聯接?
無需加入:
select id,
case when old_new = 'n' then object end as new_object,
case when old_new = 'o' then object end as old_object
from the_table
order by id;
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