创建索引的语法是create [unique|fulltext] index 索引名 on 表名字段创建普通索引create index idx_user_name on tb_users(name);上面sql语句中idx_user_name是索引名tb_users是表name是字段创建唯一索引create unique index idx_user_phone on tb_users(phone);创建联合索引create index idx_user_pas on tb_users(profession,age,status);查看索引show index from 表名show index from tb_users;删除索引drop index 索引名 on 表名drop index idx_user_email on tb_users;