This is very basic sample for adding new column to a existing table and set default value by adding constraints.
You can do this via SQL Server Management Studio but this is TSQL example!
/* This script will add new field IsManager to table Employee and set default value to 0. After creation of the field, run update statement to populate IsManager =0 for existing record. */ Go Alter Table tbl_Employee add [IsManager] [bit] NULL Go ALTER TABLE tbl_Employee ADD CONSTRAINT [DF_Employee_IsManager] DEFAULT ((0)) FOR [IsManager] Go UPDATE Employee SET [IsManager]=0