MySQL 8.0

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select version();

version()

8.0.30

create table t
( id int auto_increment primary key, val int);

insert into t values
(307,1),(308,1),(309,1),(310,1),(311,1);

Records: 5  Duplicates: 0  Warnings: 0

alter table t
	modify column id int;
	#drop primary key;
show create table t;

Records: 5  Duplicates: 0  Warnings: 0

Table
Create Table

t
CREATE TABLE `t` (
  `id` int NOT NULL,
  `val` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

update t 
	set id = id - 306;

Rows matched: 5  Changed: 5  Warnings: 0

select * from t;

id
val

1
1

2
1

3
1

4
1

5
1

alter table t
	modify column id int auto_increment;	

Records: 5  Duplicates: 0  Warnings: 0

show create table t;

Table
Create Table

t
CREATE TABLE `t` (
  `id` int NOT NULL AUTO_INCREMENT,
  `val` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci