formatting data for conditional logit

[deleted_user]

I am trying to combine a dataset that contains individual IDs and decisions (I have 27,000 observations) with another dataset that includes the 51 choices and their characteristics. Is there a way to create a new dataset that combines these two sets so that there are 51 lines of data with the choice characteristics for each ID and decision pair. If I can get it into one dataset, I can then add a new variable which is 1 if the choice and decision match and 0 otherwise.

I know this is probably simple, but I am new to SAS and I'm stuck.