For a column constraint, the name of the column that is a
    unique key or primary key in the referenced table. You cannot
    use a computed column as a referenced column name. For a table
    constraint, the referenced column name is the name of the column
    or columns that are a unique key or primary key in the referenced
    table. If you omit the referenced-column-name clause, the primary
    key is selected by default. The number of columns and their data
    types must match.