see default sql server code example
Example: how to check default value of column in sql server
SELECT object_definition(default_object_id) AS definition
FROM sys.columns
WHERE name ='colname'
AND object_id = object_id('dbo.tablename')
SELECT object_definition(default_object_id) AS definition
FROM sys.columns
WHERE name ='colname'
AND object_id = object_id('dbo.tablename')