Open 1to1 left.sav                         Open 1to1 right.sav 

Data → Merge Files → Add Cases

Select both Veggies and Fruits variables from the list of unpaired variables and click Pair

Indicating a source creates a new variable indicating whether the case

came from active (0) or non-active (1) dataset.

ADD FILES /FILE='C:\Users\nyuguest\Desktop\1to1 left.sav'

  /FILE='C:\Users\nyuguest\Desktop\1to1 right.sav'

  /RENAME Fruits=Veggies

  /IN=source.

VARIABLE LABELS source

 'Case source is DataSet2'.

EXECUTE.

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