Answer by Mohit Dagar for How to add a column with a default value to an existing table in SQL Server?

This can be done by the below code.

CREATE TABLE TestTable    (FirstCol INT NOT NULL)    GO    ------------------------------    -- Option 1    ------------------------------    -- Adding New Column    ALTER TABLE TestTable    ADD SecondCol INT    GO    -- Updating it with Default    UPDATE TestTable    SET SecondCol = 0    GO    -- Alter    ALTER TABLE TestTable    ALTER COLUMN SecondCol INT NOT NULL    GO