SAS Sort Procedure

The SORT procedure in SAS sorts data. It can optionally remove duplicated cases.

Syntax

Sort a table, either in-place or into a new table.

proc sort data=LIBREF.TABLE1 out=LIBREF.TABLE2;
    by VAR1;
run;

Deduplicate a table. Produce two tables: unique cases to TABLE2 and removed (duplicate) cases to TABLE3.

proc sort data=LIBREF.TABLE1 out=LIBREF.TABLE2 nodupkey dupout=LIBREF.TABLE3;
    by VARLIST;
run;

Examples

Basic Deduplication

proc sort data=LIBREF.OLDTABLE
          out=LIBREF.NEWTABLE
          nodupkey
          dupout=LIBREF.REMOVEDCASES
  by ID;
run;

Perfect Duplicates

To remove perfect duplicates...

1. use _all_ on the BY statement

2. substitute the nodupkey option with noduprecs

Deduplication With Criteria

If there should be a preference between which case is kept, use another SORT procedure before the one specifying nodupkey.

proc sort data=LIBREF.OLDTABLE
          out=LIBREF.TABLE1;
  by ID descending QUALITY DATE;
run;

proc sort data=LIBREF.TABLE1
          out=LIBREF.NEWTABLE
          nodupkey
          dupout=LIBREF.TABLE2
  by ID;
run;

Alternatives

CategoryRicottone