Set as identity column

Defines the column as an identity column. Only columns of type SMALLINT, INTEGER, BIGINT, DECIMAL, or NUMERIC can be created as identity columns. You are allowed only one identity column per table. When changing the properties of an existing table, only a column that you are adding can be specified as an identity column; existing columns cannot. Identity columns provide a way for you to uniquely identify every row in a table. Every time that a new row is added to a table with an identity column, the identity column value in the new row is incremented (or decremented) by the system.

See Options for identity columns for details about options.