Although it is a old feature for those who knows ORACLE but for SQL server developers it is a new feature.
Let understand it by an example. Suppose we want an auto incremented column a part from primary key which is a identity column,
then to achieve this we can use sequence feature.
We can create sequence feature by following command
“CREATE SEQUENCE StudentEnrollmentId AS INT
START WITH 2014000
INCREMENT BY 1”
so if you see above statement we have created a sequence with name StudentEnrollmentId which is an integer type sequence and first value means starting point is 2014000 and each time when we call sequence it will be incremented by 1.
We can create same sequence by screen also as shown in below figure
We have other option also as shown in below
CREATE SEQUENCE SEQUENCE_NAME
START WITH <constant>
INCREMENT BY <constant>
CYCLE | NO CYCLE
CACHE int | NO CACHE
as shown in above option we can provide minimum & maximum for sequence. We have cycle option mean restart again after reaching maximum or minimum.
Now we can use it with following way
“SELECT NEXT VALUE FOR StudentEnrollmentId”
I hope this might help you somewhere.