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
Then came Isaac Newton (1642-1727) who brought the laws of physics to the solar system. Isaac Newton explained why the planets move the way they do, by applying his laws of motion, and the force of gravitation between any two bodies, letting the force decrease with the square of the distance between the two bodies.