UNIQUE constraint on multiple columns

Create Table

CREATE TABLE Persons
(
P_Id int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255),
CONSTRAINT uc_PersonID UNIQUE (P_Id,LastName)
)

Alter Table

ALTER TABLE ControlPlanFoundryMachine
Add CONSTRAINT uc_MachName UNIQUE (MachName)