create table script with constraints in sql server 2008
Here's an example of creating a constraint at the same time as a table:

create table Table1
(
multiplier1 int,
multiplier2 int,
answer int,
constraint PK_Table1 primary key(multiplier1, multiplier2),
constraint CHK_Table1_Answer check (answer = multiplier1 * multiplier2),
check (answer / multiplier1 = multiplier2)
)


Per @Martin Smith's comment, the constraint name is optional.  The database will generate a name for the third constraint, like CK__Table1__22AA2996.

Constraints that are introduced on their own line can can refer to multiple columns.