You can use the OBJECTPROPERTY() function in SQL Server to see whether or not a table has a DEFAULT constraint.
To do this, pass the table’s object ID as the first argument, and TableHasDefaultCnst as the second argument. The function returns a 1 or a 0 depending on whether or not it has a DEFAULT constraint.
A return value of 1 means that the table has a DEFAULT constraint, and a value of 0 means that it’s not.