How can I set my auto-increment value to begin from 1 in MySQL?

You can truncate the table to set auto_increment value to start from 1 in MySQL. Let us first create a table −

mysql> create table DemoTable
(
   StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY
);
Query OK, 0 rows affected (1.44 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values();
Query OK, 1 row affected (0.35 sec)
mysql> insert into DemoTable values();
Query OK, 1 row affected (0.30 sec)
mysql> insert into DemoTable values();
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values();
Query OK, 1 row affected (0.06 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-----------+
| StudentId |
+-----------+
|         1 |
|         2 |
|         3 |
|         4 |
+-----------+
4 rows in set (0.00 sec)

Now, if you will insert more values, then the StudentId, which is AUTO_INCREMENT will continue from 5. To avoid this, first, truncate the table −

Following is the query to truncate the table to start auto_increment value from 1 −

mysql> truncate table DemoTable;
Query OK, 0 rows affected (0.93 sec)
mysql> select *from DemoTable;
Empty set (0.00 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values();
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values();
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values();
Query OK, 1 row affected (0.07 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output. Now, since we truncated the table above, therefore the AUTO_INCREMENT begins from 1 again as shown in the below output −

+-----------+
| StudentId |
+-----------+
|         1 |
|         2 |
|         3 |
+-----------+
3 rows in set (0.00 sec)