Purpose of sample: show how a column constraint can be created.

Table tbl = new Table (db, "MyTestTable");
Column c1 = new Column(tbl, "c1", DataType.DateTime);
c1.AddDefaultConstraint(/*name optional*/);
c1.DefaultConstraint.Text = "getdate()";
tbl.Columns.Add(c1);
tbl.Create();

Disclaimer: this sample doesn't handle exceptions and may not function as expected. Use at own risk. It is good practice to test an application before using it in production.