Join Types:

Join Types:
Prev	MERGEJOIN	Next

The following jointypes produce the following types of results, based on the records matching produced by the joincondition:

INNER	Only those records that exist in all datasets in the setofdatasets.
LEFT OUTER	At least one record for every record in the first dataset in the setofdatasets.
LEFT ONLY	One record for every record in the first dataset in the setofdatasets for which there is no match in any of the subsequent datasets.
MOFN(min [,max])	One record for every record with matching records in min number of adjacent datasets within the setofdatasets. If max is specified, the record is not included if max number of dataset matches are exceeded.

Example:

Rec := RECORD,MAXLENGTH(4096)
  STRING1 Letter;
  UNSIGNED1 DS;
END;
ds1 := DATASET([{'A',1},{'B',1},{'C',1},{'D',1},{'E',1}],Rec);
ds2 := DATASET([{'A',2},{'B',2},{'H',2},{'I',2},{'J',2}],Rec);
ds3 := DATASET([{'B',3},{'C',3},{'M',3},{'N',3},{'O',3}],Rec);
ds4 := DATASET([{'A',4},{'B',4},{'R',4},{'S',4},{'T',4}],Rec);
ds5 := DATASET([{'B',5},{'V',5},{'W',5},{'X',5},{'Y',5}],Rec);
SetDS := [ds1,ds2,ds3,ds4,ds5];
j1 := MERGEJOIN(SetDS,
                STEPPED(LEFT.Letter=RIGHT.Letter),
                SORTED(Letter));
j2 := MERGEJOIN(SetDS,
                STEPPED(LEFT.Letter=RIGHT.Letter),
                SORTED(Letter),LEFT OUTER);
j3 := MERGEJOIN(SetDS,
                STEPPED(LEFT.Letter=RIGHT.Letter),
                SORTED(Letter),LEFT ONLY);
j4 := MERGEJOIN(SetDS,
                STEPPED(LEFT.Letter=RIGHT.Letter),
                SORTED(Letter),MOFN(3));
j5 := MERGEJOIN(SetDS,
                STEPPED(LEFT.Letter=RIGHT.Letter),
                SORTED(Letter),MOFN(3,4));
OUTPUT(j1);
OUTPUT(j2);
OUTPUT(j3);
OUTPUT(j4);
OUTPUT(j5);