MySQL build library, build tables, complement columns

SET NAMES
  UTF8;
DROP DATABASE IF EXISTS
  TMOOC;
  CREATE DATABASE TMOOC Charset=utf8;
  Use TMOOC;
CREATE TABLE Stu (
  Sid INT PRIMARY KEY auto_increment,
  Sname VARCHAR (+) UNIQUE,
  Score DOUBLE,
  Schooltime DATE
);
INSERT into Stu (sname,schooltime) VALUES ("Shu", now ());
INSERT into Stu (sname,schooltime) VALUES ("EN", now ());
INSERT into Stu (sname,schooltime) VALUES ("Huang", now ());
INSERT into Stu (sname,schooltime) VALUES ("HSE", now ());
--Solve the problem, create table errors, one less column, the following statement can complement a sentence
ALTER TABLE Stu ADD score DOUBLE (10,2);
--Assign the initial value to the score, or it will default to NULL
UPDATE Stu SET score=0;

MySQL build library, build tables, complement columns