Solution to an exercise for joining and concatenating data. Combine data tables side-by-side using the join operation. Put tables on top of each other with the concatenate operation. CHECK YOUR ANSWERS: Joiner: The number of rows is 32549 in all joined tables. No rows were discarded in the joining operations. Concatenate: The ID column is missing in the adult_scotland table. You need to select union of columns, if you want to include the ID column in the concatenated table.