索引操作

创建非唯一索引

CREATE INDEX person_num ON person (number);
或者
ALTER TABLE person ADD INDEX person_num (number)；

创建唯一索引

CREATE UNIQUE INDEX person_num ON person (number);
或者
ALTER TABLE person ADD UNIQUE person_num  on (number);

查看表内所有索引

SHOW INDEX from person;

删除索引

DROP INDEX person_num ON person;
ALTER TABLE person DROP INDEX person_num;