These solutions work only for situations where the sequential key starting number can be reset (set to 1) at each run.

This simple method involves the system variable @INROWNUM or a stage variable. Whether this solution works depends on your schema or table definitions. When you require a system generated sequential key for a table this method will allow you to create one quickly which is reset to 1 for each run.

After you have your output columns defined open the transformer stage (double click on the transformer symbol) & open the stage variables properties box.

Opening the stage variables properties box is opened by RIGHT-clicking on the stage variables box within the transformer GUI. If your stage variables box is not displayed in the transformer press the "Show/Hide Stage variables" button on the transformer toolbar .

In the stage variables box enter a meaningful name for the variable which will contain the Sequential key & set it's initial value to 0 (zero).

Now all that is left is to use the variable in the derivation of your key field as shown below.

The process can be simplified by placing @INROWNUM in the derivation of the field in the TableOut link however, I prefer this method as these keys are often used in multiple links. The stage variable makes modification or maintenance of the key simpler & more straightforward. Experiment with the methods & select the best for your situation.

If @INROWNUM is not providing desirable results you can define the derivation of the Stage variable as shown below. Again, a simple solution which is reset to 1 each time the process is run.