SQL加入Table/映射
SQL JOIN Table/ mapping
你好，
我有 2 个简单的表，我必须进行一个映射数据的查询，如下例所示。我使用甲骨文 SQL 。请帮助我:)
Table一个
ID | A1 | A2 | A3 | Year
---+----+----+----+-----
1 |3 | 5 | 7 | 2000
2 |4 | | 5 | 2001
Table B
Atribute | Values
---------+------------
3 | Apple
4 | Lime
5 | Pineapple
6 | Apricot
7 | Mango
结果
ID | A1 | A2 | A3 | Year
----+-------+------------+------------+-------
1 | Apple | Pineapple | Mango | 2000
2 | Lime | | Pineapple | 2001
使用不同的别名多次加入btable
select a.id, a.year,
b1.values as a1,
b2.values as a2,
b3.values as a3
from a
left join b b1 on a.a1 = b1.attribute
left join b b2 on a.a2 = b2.attribute
left join b b3 on a.a3 = b3.attribute
你好， 我有 2 个简单的表，我必须进行一个映射数据的查询，如下例所示。我使用甲骨文 SQL 。请帮助我:)
Table一个
ID | A1 | A2 | A3 | Year
---+----+----+----+-----
1 |3 | 5 | 7 | 2000
2 |4 | | 5 | 2001
Table B
Atribute | Values
---------+------------
3 | Apple
4 | Lime
5 | Pineapple
6 | Apricot
7 | Mango
结果
ID | A1 | A2 | A3 | Year
----+-------+------------+------------+-------
1 | Apple | Pineapple | Mango | 2000
2 | Lime | | Pineapple | 2001
使用不同的别名多次加入btable
select a.id, a.year,
b1.values as a1,
b2.values as a2,
b3.values as a3
from a
left join b b1 on a.a1 = b1.attribute
left join b b2 on a.a2 = b2.attribute
left join b b3 on a.a3 = b3.attribute