Shifting values of rows in MySQL to change the existing id values for existing rows?

Let us first create a table −

mysql> create table DemoTable
   -> (
   -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> StudentName varchar(20)
   -> );
Query OK, 0 rows affected (1.07 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable(StudentName) values('Chris');
Query OK, 1 row affected (0.23 sec)
mysql> insert into DemoTable(StudentName) values('Robert');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable(StudentName) values('David');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable(StudentName) values('Mike');
Query OK, 1 row affected (0.10 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
|         1 | Chris       |
|         2 | Robert      |
|         3 | David       |
|         4 | Mike        |
+-----------+-------------+
4 rows in set (0.00 sec)

Here is the query to shift id values of existing rows in MySQL −

mysql> update DemoTable set StudentId=StudentId+1000;
Query OK, 4 rows affected (0.18 sec)
Rows matched: 4 Changed: 4 Warnings: 0

Let us check the table records once again −

mysql> select *from DemoTable;

This will produce the following output −

+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
|      1001 | Chris       |
|      1002 | Robert      |
|      1003 | David       |
|      1004 | Mike        |
+-----------+-------------+
4 rows in set (0.00 sec)