【数据库SQL实战】对first_name创建唯一索引uniq_idx_firstname

https://www.nowcoder.com/practice/e1824daa0c49404aa602cf0cb34bdd75?tpId=82&tqId=29805&rp=0&ru=/ta/sql&qru=/ta/sql/question-ranking

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);