Database Reference
In-Depth Information
from the initial value that was defined. This property is disabled for reusable
Sequence Generator transformations.
•
Tracing Level
: This indicates the level of detail you wish to write into the session
log. We will discuss this option in detail later in the chapter.
With this, we have seen all the properties of the Sequence Generator transformation.
Let's talk about the usage of the Sequence Generator transformation:
•
Generating a primary/foreign key
: The sequence generator can be used to gen-
erate a primary key and foreign key. The primary key and foreign key should be
unique and not null. The Sequence Generator transformation can easily do this, as
seen here. Connect the
NEXTVAL
port to the targets for which you wish to gener-
ate the primary and foreign key, as shown in the following screenshot:
•
Replace the missing values
: You can use the Sequence Generator transformation
to replace missing values by using IIF and ISNULL functions. Consider that you
have some data with
JOB_ID
of an employee. Some records do not have
JOB_ID
in the table. Use the following function to replace these missing values.
Make sure you are not generating
NEXTVAL
in a manner similar to existing
JOB_ID
in the data:
IIF( ISNULL (JOB_ID), NEXTVAL, JOB_ID)
