mysql 02

CREATE TABLE emp(
eid INT,
ename VARCHAR(20),
egender CHAR(2),
ebirthday DATE,
eemail CHAR(10),
eramark VARCHAR(50)
);
/*增加age*/
ALTER TABLE emp ADD COLUMN eage CHAR(2);
/*查询所有*/
SELECT * FROM emp;
/*修改email'长度为50*/
 ALTER TABLE emp MODIFY COLUMN eemail VARCHAR(50);
 /*删除ramark*/
 ALTER TABLE emp DROP COLUMN eramark;
 /*列名name改为usename*/
 ALTER TABLE emp CHANGE COLUMN ename eusename VARCHAR(2);