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The auto_increment is a default property that automatically increments the newly added record
by 1. The auto_increment can be changed from the beginning as well. The procedure for that is
given below − First, a table is created. mysql> CREATE table DemoAuto
-> (
-> id int auto_increment,
-> name varchar(100),
-> primary key(id)
-> );
Query OK, 0 rows affected (0.47 sec) 登录后复制 After that the alter table command is used to change the starting number of auto_incremnt
which starts from 1 by default. The starting value is changed to 100. mysql> alter table DemoAuto auto_increment = 100;
Query OK, 0 rows affected (0.24 sec)
Records: 0 Duplicates: 0 Warnings: 0 登录后复制 Then some records are inserted into the table.This is given as follows − mysql> INSERT into DemoAuto(name) values('John');
Query OK, 1 row affected (0.10 sec)
mysql> INSERT into DemoAuto(name) values('Smith');
Query OK, 1 row affected (0.13 sec)
mysql> INSERT into DemoAuto(name) values('Bob');
Query OK, 1 row affected (0.22 sec)登录后复制 The select statement is used to obtain the table values as output. This is given below − mysql> SELECT * from DemoAuto;
登录后复制 The following is the output obtained − +-----+-------+
| id | name |
+-----+-------+
| 100 | John |
| 101 | Smith |
| 102 | Bob |
+-----+-------+
3 rows in set (0.00 sec) 登录后复制 In the above output, the record id starts from 100. |
