In Alteryx, when we don't have row ID we can just put a Record Id tool in that creates them. How do we do that in Tableau Prep?
There's not a straightforward function in Tableau Prep. But with these 2 steps can create row IDs.:

Step 1.

Create a dummy field assigning '1' to each row to ORDERBY so it's not reordering the data.

Step 2.

Create the RowID field by using the ROW_NUMBER() formula and ORDERBY the dummy field. This will assign a number to each row without changing the order of the rows.