BY Subcommand (MATCH FILES command)
BY
specifies
one or more identification, or key, variables that determine which
cases are to be combined. When BY
is specified, cases from one file are matched only with cases from
other files that have the same values for the key variables. BY
is required unless all input files are
to be matched sequentially according to the order of cases.
-
BY
must follow theFILE
andTABLE
subcommands and any associatedRENAME
andIN
subcommands. -
BY
specifies the names of one or more key variables. The key variables must exist in all input files. The key variables can be numeric or long or short strings. - All input files must be sorted in ascending order
of the key variables. If necessary, use
SORT CASES
beforeMATCH FILES
. - Missing values for key variables are handled like any other values.
- Unmatched cases are assigned system-missing values (for numeric variables) or blanks (for string variables) for variables from files that do not contain a match.