I have a large dataset of over 4000 cases with over 500 variables. I want to add this set of variables to another dataset containing most of the same cases but only around 10 variables.
Both of the datasets contain an ID variable that allows me to match the cases. The larger dataset is a keyed table because there are cases in there that aren't in the smaller set and are therefore of no interest to me.
I'm very comfortable with merging the files but my problem arises when I look at the new dataset. The variables are in there but all the values turn up missing. This only applies to the variables that were added to the active dataset. I checked to see if the key variable had any duplicates and it didn't.
I wonder why this happens, and if there is a way to fix this? I can add that I have done this very often before without this problem.