alter table table_name add constraint primary_cons
primary key(id)------------------------
| |
| 相逢何必曾相识 |
| |
------------------------
primary key(id)------------------------
| |
| 相逢何必曾相识 |
| |
------------------------
ALTER TABLE table MODIFY(
COLUMN DATATYPE PRIMARY KEY);
alter table table_name add constraint primary_cons
primary key(id)