How to reset the primary key of a table in mysql?
The reset the primary key of a table means to reset the auto_increment property to 1. The syntax is as follows to reset the primary key of a table.
alter table yourTableName auto_increment = 1;
To understand, let us create a table −
mysql> create table ResetPrimaryKey
−> (
−> Id int auto_increment,
−> PRIMARY KEY(Id)
−> );
Query OK, 0 rows affected (0.59 sec)
Insert some records into the table. The query to insert records is as follows −
mysql> insert into ResetPrimaryKey values();
Query OK, 1 row affected (0.18 sec)
mysql> insert into ResetPrimaryKey values();
Query OK, 1 row affected (0.15 sec)
mysql> insert into ResetPrimaryKey values();
Query OK, 1 row affected (0.09 sec)
mysql> insert into ResetPrimaryKey values();
Query OK, 1 row affected (0.09 sec)
Now you can display all records with the help of select statement. The query is as follows −
mysql> select *from ResetPrimaryKey;
The following is the output that displays only the ID, which is a Primary Key:
+----+
| Id |
+----+
| 1 |
| 2 |
| 3 |
| 4 |
+----+
4 rows in set (0.00 sec)
Here is the query to reset the primary key of a table using alter −
mysql> alter table ResetPrimaryKey auto_increment = 1;
Query OK, 0 rows affected (0.21 sec)
Records: 0 Duplicates: 0 Warnings: 0
The query to check that we have added auto_increment property successfully or not:
mysql> desc ResetPrimaryKey;
The following is the output −
+-------+---------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+----------------+
| Id | int(11) | NO | PRI | NULL | auto_increment |
+-------+---------+------+-----+---------+----------------+
1 row in set (0.11 sec)
Published on 10-Jan-2019 07:56:04
