Mysql defines a primary key as an automatically increasing Identifier type.

Mysql defines the primary key as the automatic growth Identifier type. in this article, we will share how mysql defines the primary key as the automatic growth Identifier type.

1. define the primary key as the automatic growth Identifier type in mysql. if the primary key of the table is set to the auto_increment type, the database automatically assigns a value to the primary key. For example:

Create table MERS (id int auto_increment primary key notnull, name varchar (15); insert into MERS (name) values ("name1"), ("name2 ");

Once the id is set to auto_increment type, mysql database automatically assigns a value to the primary key in ascending mode.

In MS SQLServer, if the table's primary key is set to the identity type, the database automatically assigns a value to the primary key. For example:

Create table MERS (id int identity (1, 1) primary key notnull, name varchar (15); -- www. jbxue. cominsert into MERS (name) values ("name1"), ("name2"); select id from customers;

The query result is the same as that of mysql. It can be seen that, once the id is set to the identity type, the MSSQLServer database automatically assigns a value to the primary key in ascending mode.