Hello, I found some confusing thing while constructing queries. Let's assume I have a simple model with 2 classes: public static class Product { private BigInteger productId; public Product(int id) { productId = BigInteger.valueOf((long)id); } public void setProductId(BigInteger productId) { this.productId = productId; } public BigInteger getProductId() { return productId; } } public static class Relation { private BigInteger productAID; private Product productB; public void setProductAID(BigInteger productAID) { this.productAID = productAID; } public BigInteger getProductAID() { return productAID; } public void setProductB(Product productB) { this.productB = productB; } public Product getProductB() { return productB; } } It's not very sophisticated. And I have a query: query "Query_1" (Product $p) $r : Relation( productAID == $p.productId ) end The problem is, that, when I want to build a DRL with the query I've got an error: org.drools.rule.InvalidRulePackage: Not possible to directly access the property 'productId' of declaration '$p' since it is not a pattern : [Rule name=Query_1, agendaGroup=MAIN, salience=0, no-loop=false] Unable to create restriction '[QualifiedIndentifierRestr: == $p.productId ]' for field 'productAID' in the rule 'Query_1' : [Rule name=Query_1, agendaGroup=MAIN, salience=0, no-loop=false] The question is: why? Of course, all types are imported, etc. Moreover, when I modify the query as a following: query "Query_1" (Product $p) $p1 : Product ( ) from $p $r : Relation( productAID == $p1.productId ) end then everything works fine. Is it a desirable behaviour? I hope the description above is enough to understand the problem, but if anyone needed full Java source and DRLs, please, let me know. Best regards, -- Przemysław Różycki AMG.net, A Bull Group Company ul. Łąkowa 29 90-554 Łódź www.amg.net.pl