题解 | #对first_name创建唯一索引#
对first_name创建唯一索引uniq_idx_firstname
https://www.nowcoder.com/practice/e1824daa0c49404aa602cf0cb34bdd75
方法1.Create创建索引
create unique index uniq_idx_firstname on actor (first_name); create index idx_lastname on actor (last_name);
方法2.Alter创建索引
alter table actor
add unique uniq_idx_firstname(first_name);
alter table actor
add index idx_lastname(last_name);
