title: Insertin new column into table with condition
body: <p>I have a table Plane where is column made_in_year (INT) and i need a new column <strong>last_repair (datetime) NOT NULL</strong> and it need to have condition which is <strong>last_repair>= made_in_year</strong> and i'm not sure how to add that condition or what syntax i should use...
  I know i have to use <strong>ALTER TABLE Plane ALTER COLUMN last_repair DATETIME xxxxxxxxx</strong> and what should i use instead of xxxxxx?</p>