mysql索引操作

查看表索引

show index from school;

desc school;

添加普通索引

alter table school add index idx_name(`name`);

create index index_name on school(`name`);

添加唯一索引

create unique index uni_name on school(`name`);

alter table school add unique uni_name(`name`);

添加主键

alter table school add primary key(`id`);

添加AUTO_INCREMENT约束

alter table school modify column `id` bigint(20) NOT NUll AUTO_INCREMENT COMMENT 'id';

删除普通索引

drop index index_name on school;

alter table school drop index idx_name;

删除唯一索引

alter table school drop index uni_name;

ALTER TABLE tablename ADD PRIMARY KEY (列的列表); 

删除主键

删除id的auto_increment约束

alter table school change id id int;

删除id的primary key约束

alter table school drop primary key;