The HASHBYTES() function doesn't support a multiple column list like CHECKSUM(), however, a while back I found a solution to this by appending multiple columns after re-casting to VarBinary datatype.

For example:

print hashbytes('MD5',cast('John' as varbinary(99)) + cast('Doe' as varbinary(99)));

0x9FD9F63E0D6487537569075DA85A0C7F

You can also add a computed column that consists of a hash of multiple columns like so:

create table Employee

(

EmployeeID int not null,

EmployeeFName varchar(30) not null,

EmployeeLName varchar(30) not null,

EmployeeHash as hashbytes('MD5',cast(EmployeeFName as varbinary(99)) + cast(EmployeeLName as varbinary(99))) persisted

);

insert into Employee

values (1,'John','Wilkerson'), (2,'Susan','Phelps-Jamseson');

select * from Employee;