SPSS Statistics provides you with several commands to merge files. You can perform a one-to-many merge using either STAR JOIN or MATCH FILES. STAR JOIN is a more recent addition to SPSS Statistics and is more flexible.
You can perform a one-to-one merge using MATCH FILES, which enables you to perform both parallel and non-parallel matches. Any of the aforementioned merges rely on key fields for the matching.
Finally, you can use ADD FILES to combine cases from multiple file sources.
In the next chapter, we turn to two important topics: aggregating and restructuring data.