Concat使用两个不同的表

Question

如何根据此代码从两个不同的表中合并两列（wmsmatch.barcode和externalb.checkd）：

select * from wmsmatch join outerb on wmsmatch.id = outerb.id

`

Table: wmsmatch
Columns:
id int(10) 
barcode varchar(100)

Table: outerb
Columns:
Product_Code varchar(100) 
Brand varchar(100) 
Product varchar(100) 
Size varchar(100) 
Barcode varchar(100) 
Checkd varchar(100) 
id int(11) AI PK

Answer 1

select CONCAT(wmsmatch.barcode , outerb.checkd) as concat_field, *
from wmsmatch 
join outerb on wmsmatch.id = outerb.id

Answer 2

SELECT CONCAT(wmsmatch.barcode, outerb.checkd) 
FROM wmsmatch, outerb WHERE wmsmatch.id = outerb.id;