Drop default constraint

This script identifies a column's default constraint (if any) and drops it:

DECLARE @sql NVARCHAR(MAX)
 
SELECT 
  @sql = 'ALTER TABLE [' + s.name + '].[' + o.name + ']
DROP CONSTRAINT [' + dc.name + ']'
FROM sys.schemas s
  INNER JOIN sys.objects o ON o.schema_id = s.schema_id
  INNER JOIN sys.columns c ON c.object_id = o.object_id
  INNER JOIN sys.default_constraints dc 
    ON dc.parent_object_id = o.object_id
    AND dc.parent_column_id = c.column_id
WHERE s.name = 'schemaName'
AND o.name = 'tableName'
AND c.name = 'columnName'
 
PRINT @sql
EXEC(@sql)