How to place a unique constraint for multiple columns? (4292803)

Is it possible to create a unique constraint that contains multiple columns of a table? Under the table's Attributes tab, you can select any row and double click on the Unique column to assign that row as a unique constraint but this would only apply to each row individually. How can I include multiple columns in one unique constraint?

Use the Alternate Keys tab to generate the unique constraint for multiple columns.

1. Double click on the entity
2. Go to the Alternate Keys tab | click on New.
3. Enter a name and physical name
4. Select the columns you wish to include in the constraint and hit OK.