数据库SQL实战题：对first_name创建唯一索引uniq_idx_firstname（教程）

针对如下表actor结构创建索引：

CREATE TABLE IF NOT EXISTS actor (

actor_id smallint(5) NOT NULL PRIMARY KEY,

first_name varchar(45) NOT NULL,

last_name varchar(45) NOT NULL,

last_update timestamp NOT NULL DEFAULT (datetime(‘now’,’localtime’)))

对first_name创建唯一索引uniq_idx_firstname，对last_name创建普通索引idx_lastname

【注意actor和()间不能有空格！】

即

create index idx_lastname on actor(last_name);  
create index idx_lastname on actor (last_name); 

//创建唯一索引
create unique index uniq_idx_firstname on actor(first_name);
//创建普通索引
create index idx_lastname on actor(last_name);