The following examples illustrate the use of subsets.
Example 1
This example includes the following subsets:
-
SS-E1, which is a subset of the embedded data set E
-
SS-E2, which is a subset of the set S-E
-
SS-D1, SS-D2, and SS-D3, all of which are subsets of the data set D
-
SS-D4, which is a subset of the set S-D
D DATA SET
(
D1 ALPHA(10);
D2 BOOLEAN;
D3 FIELD(8);
D4 NUMBER(S5,2);
E DATA SET
(
E1 REAL;
E2 NUMBER(5);
E3 GROUP
(
E31 BOOLEAN;
E32 ALPHA(5);
);
);
S-E SET OF E
KEY E2;
SS-E1 SUBSET OF E
WHERE E1 > 0
KEY E3;
SS-E2 SUBSET OF S-E;
);
S-D SET OF D
KEY D3;
SS-D1 SUBSET OF D
WHERE D2
BIT VECTOR;
SS-D2 SUBSET OF D
LIST
DATA(D4,D2);
SS-D3 SUBSET OF D
WHERE D4>0 AND D1 NEQ " "
KEY D3
I-R
DUPLICATES LAST;
SS-D4 SUBSET OF S-D
WHERE D3>D4;Example 2
Subset T references data set D and is maintained as an ordered list.
D DATA SET ( A ALPHA(4); N NUMBER(S4,2); ); S SET OF D KEY IS N, ORDERED LIST; T SUBSET OF S WHERE N GEQ 10.5;
