Mysql self-increment column primary key

In MySQL if there is

ID Int auto_increment, CID varchar (36).

Typically, the ID is set as the primary key.

If you want to set the CID as the primary key. The self-increment column ID must be a unique index.

CREATE TABLE Temp (   ID                   bigint NOT NULL auto_increment comment ' number ',   CID           varchar ($) NOT NULL,   creat ETime           datetime NOT NULL default now () Comment ' creation time ',   unique (ID),  --Unique index  primary key (CID)--primary key); create Index index_createtime on TEMP--Clustered index (   createtime);

　　

Mysql self-increment column primary key