員工排班示例的編輯規則

Question

我目前正在為我的項目實施此程序。

我需要為“每位員工每周最多四個班次分配”添加一條規則。 我是java和drool的新手。 有沒有一種簡單的方法可以編輯以下規則以匹配我要尋找的約束？

rule "At most one shift assignment per day per employee"
when
    $s : Shift(
            employee != null,
            $e : employee,
            $leftDay : startDateTime.toLocalDate())
    Shift(
            employee == $e,
            startDateTime.toLocalDate() == $leftDay,
            this != $s)
then
    scoreHolder.addHardConstraintMatch(kcontext, -10);
end

Answer 1

您可以嘗試使用累加

您的規則可能看起來像這樣（我尚未測試過，但是它應該為您指明正確的方向）：

rule "At most four shift assignment per week per employee"
when
    $shiftWeek: ShiftWeek() //assuming this is some kind of problemfact you have in your session
    $employee: Employee()
    $count: Number(intValue() > 4) //conditional, only fire rule when $count > 4
        from accumulate(
            $shift: Shift(
                $employee == employee,
                $shiftWeek == shiftWeek
            ),
            count($shift)
        )
then
    scoreHolder.addHardConstraintMatch(kcontext, 4 - $count.intValue()); //You could also just do "- $count.intValue()", but I like the constraint match to start at -1
end