Colum '_' cannot be resolved in Trino

[#1]

I'm new to hive trino. I would like to concatenate three text columns with "_" as separator. So I wrote following code

select A.*,B.Name_group,mail_group,Occupation_group,CONCAT_WS("_",mail_group,Occupation_group,Name_group) combined_error from hive.employee.Job A left join hive.employee.Name B on A.Name_id=B.Name_id left join hive.employee.mail C on A.mail_id= C.mail_id left join hive.employee.Occupation D on A.Occupation_id=D.Occupation_id

But I got following error message

Colum '_' cannot be resolved. Can you help me to fix the issue

[#2]

@TrinoHelp ,

Double-quotes in SQL are used to specify column names. Try using single-quotes instead.

Cheers,

André