MySQL数据库原理学习（八）

CREATE [ UNIQUE | FULLTEXT ] INDEX index_name ON table_name (
index_col_name,... ) ;

SHOW INDEX FROM table_name ;

DROP INDEX index_name ON table_name ;

create table tb_user(
id int primary key auto_increment comment '主键',
name varchar(50) not null comment '用户名',
phone varchar(11) not null comment '手机号',
email varchar(100) comment '邮箱',
profession varchar(11) comment '专业',
age tinyint unsigned comment '年龄',
gender char(1) comment '性别 , 1: 男, 2: 女',
status char(1) comment '状态',
createtime datetime comment '创建时间'
) comment '系统用户表';
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('吕布', '17799990000', 'lvbu666@163.com', '软件工程', 23, '1',
'6', '2001-02-02 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('曹操', '17799990001', 'caocao666@qq.com', '通讯工程', 33,
'1', '0', '2001-03-05 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('赵云', '17799990002', '17799990@139.com', '英语', 34, '1',
'2', '2002-03-02 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('孙悟空', '17799990003', '17799990@sina.com', '工程造价', 54,
'1', '0', '2001-07-02 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('花木兰', '17799990004', '19980729@sina.com', '软件工程', 23,
'2', '1', '2001-04-22 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('大乔', '17799990005', 'daqiao666@sina.com', '舞蹈', 22, '2',
'0', '2001-02-07 00:00:00');
INSERT INTO tb_user (name, phone, email, profession, age, gender, status,
createtime) VALUES ('露娜', '17799990006', 'luna_love@sina.com', '应用数学', 24,
'2', '0', '2001-02-08 00:00:00');

CREATE INDEX idx_user_name ON tb_user(name);

 CREATE UNIQUE INDEX idx_user_phone ON tb_user(phone);

CREATE INDEX idx_user_pro_age_sta ON tb_user(profession,age,status);

CREATE INDEX idx_email ON tb_user(email);

show index from tb_user;