Here are some examples of Oracle alter table syntax to modify data columns and note that you can add constraints like NOT NULL: ALTER TABLE customer MODIFY (cust_name varchar2(100) not null, cust_hair_color varchar2(20)) ;
Did Sir Isaac Newton write any books? His best known book is Principia (Philosophiae Naturalis Principia Mathematica) published in 1687; which includes his laws of motion. Edit
It was while Galileo was under house arrest that he wrote one of his finest works, Two New Sciences. Here he summarized the work he had done some forty years earlier, on the two sciences now called kinematics and strength of materials.