我正在使用MySQL和DOMO。我有两个表,我想在两列上都加入。我的数据如下:
第一张表代表2019年收入
Week Name 2019 Revenue
1 Paul 576356
1 Nick 246564
2 Sam 426547265
2 Frank 5436
另一张表代表2020年收入
Week Name 2020 Revenue
1 Paul 554
1 Nick 200
2 Sam 400
2 Frank 500
我希望输出为:
Week Name 2019 Revenue 2020 Revenue
1 Paul 576356 554
1 Nick 246564 200
2 Sam 426547265 400
2 Frank 5436 500
我尝试过以下几种:
SELECT
`Week`,
`Advertiser`,
`2019 Revenue`
from `2019` as a
left join `2020` as b
on a.`Week` = b.`Week`
and a.`Advertiser` = b.`Advertiser`
错误消息:违反了SQL约束:字段列表中的列"周"不明确
答案应该是显而易见的。但解决方案是,您养成了在查询中总是限定列名的习惯:
SELECT a.Week, a.Advertiser, a.`2019 Revenue`, b.`2020 Revenue`
from `2019` a left join
`2020` b
on a.Week = b.Week and
a.Advertiser = b.Advertiser;