drools decision table exists keyword

Question

currently my drools decision table looks like next:

|CONDITION|CONDITION|
---------------------
|      Person       |
---------------------
|name=$1  |age=$1   |
---------------------
|         |         |
---------------------
|a        |22       |
---------------------
|b        |33       |
---------------------

now i want to make this decision table looks like next in .drl file :

rule "1"
when
    exist Person(name=="a",age="22")
then
    do something
end

rule "2"
when 
    Person(name="b", age="33")
then
    do something
end

so how to modify the decision table to achieve my goal?

that is how to use 'exists' keyword in decision table file?

thanks in advance!

laune laune · Accepted Answer · 2014-07-21T08:08:38

| CONDITION  | CONDITION |
--------------------------
|     exists Person()    |
-------------------------
|name==$param|age==$param|
---------------------
|            |           |
---------------------------
|a           |22         |
---------------------------
|b           |33         |
--------------------------

The other rule is almost the same; just omit the exists. However, one such table can only produce rules according to one template. Therefore, you'll get either two rules (a/22, b/33) with exists, or the same pair without.

To have rules according to both templates, you need two different RuleTables.

drools decision table exists keyword

1 Answers