How to add a Default constraint while creating a table? SQL Server
You can name the constraint inline:
CREATE TABLE tblTest(
  --
  --
  Gender int CONSTRAINT DF_tblTest_Gender DEFAULT 3,
  --
) ;

As the CREATE TABLE msdn page shows:

DEFAULT
... To maintain compatibility with earlier versions of SQL Server, a constraint name can be assigned to a DEFAULT.

In the same page, we can find that the only options for &lt;table_constraint&gt; are PRIMARY KEY, FOREIGN KEY and CHECK constraints:

&lt; table_constraint &gt; ::=  
  [ CONSTRAINT constraint_name ]   
{  
   { PRIMARY KEY | UNIQUE }  
       {   
         NONCLUSTERED (column [ ASC | DESC ] [ ,... n ])  
         | NONCLUSTERED HASH (column [ ,... n ] ) 
               WITH ( BUCKET_COUNT = bucket_count )   
       }   
    | FOREIGN KEY   
        ( column [ ,...n ] )   
        REFERENCES referenced_table_name [ ( ref_column [ ,...n ] ) ]   
    | CHECK ( logical_expression )   
}


so if you want to add a default constraint (naming or not) the only ways are by doing it inline or with an ALTER TABLE statement.