DB2 : What is the need of Identity Column?
Deepak Verma
Identity column allows the insertion of incremental values in a particular column whenever a row is inserted in the table. We can define the initial value and the seed value as well when declaring an identity column.
When a new row is created in a table with Identity Column, the Identity Column value for inserted row is generated by the system automatically. A table can have only one identity column.To know how it be possible refer this link :Click Here