![](/img/trans.png)
[英]Combining multiple SQL queries of same type in a single result set in PostgreSQL
[英]PostgreSQL - Combining result-rows from multiple queries
我很難將來自同一table.column的兩個列加在一起,並具有兩個不同的值。
如何將以下兩個查詢加在一起,以給出兩個各自具有各自值的新列;
SELECT
... more columns ...
components.description,
FROM
...
WHERE
graphiccards.id = systems.id AND
components.id = graphiccards.component_id;
SELECT
components.description
FROM
...
WHERE
components.id = mainboards.component_id AND
mainboards.id = systems.mainboard_id
我希望這兩個結果在兩個不同列的同一行中。
您可能希望看一下UNION
運算符
select
components.description
stuff as second_column
from mytable where conditions
union
select
components.description
stuff2 as second_column
from mytable2 where conditions2
您只需要確保具有相同名稱的相同nr列即可。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.