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
Newton left for the countryside, where he made his main discoveries. In 1667, he returned to teach at the university and continued his studies. In 1687, Newton first published his important discoveries in his Principia, which became the basic book of physics. For a short period, Newton represented the university in the English Parliament, then moved to London, where he presided over the Royal Society (the leading scientific society) until his death.