Compare value expressions. Relational operators are used in
conditional expressions. See the table in the list of subtopics
for a summary of the RDML relational operators.
1 – Table
Relational Value
Operator
-------------------------------------------------------------
EQ = True if the two value expressions are
equal.
NE <> True if the two value expressions are
not equal.
GT > True if the first value expression is
greater than the second.
GE >= True if the first value expression is
greater than or equal to the second.
LT < True if the first value expression is
less than the second.
LE <= True if the first value expression is
less than or equal to the second.
-------------------------------------------------------------
Note: In all cases, if either value expression is
missing, the value of the condition is missing.
2 – Examples
The following programs demonstrate the use of the LE (less than
or equal to) operator in a FOR statement. The programs create a
record stream of all those employees who have an employee ID less
than or equal to 00400. The programs then print the employee IDs
from the records in the record stream.
2.1 – C Example
#include <stdio.h>
DATABASE PERS = FILENAME "PERSONNEL";
main()
{
READY PERS;
START_TRANSACTION READ_WRITE;
FOR E IN EMPLOYEES WITH E.EMPLOYEE_ID LE "00400"
printf ("%s\n", E.EMPLOYEE_ID);
END_FOR;
COMMIT;
FINISH;
}
2.2 – Pascal Example
program relation (input,output);
DATABASE PERS = FILENAME 'PERSONNEL';
begin
READY PERS;
START_TRANSACTION READ_ONLY;
FOR E IN EMPLOYEES WITH E.EMPLOYEE_ID LE '00400'
writeln (E.EMPLOYEE_ID);
END_FOR;
COMMIT;
FINISH;
end.