Joe, The query language was scoped to be simple to implement. It is not intended to be a fully general query language. For more complex requirements, services can implement a standard query language. SPARQL is recommended.
1. Correct. What semantics do you want for multi-value properties? Are you looking for the existence of one value that does not equal the given value? 2. Correct. However, you could approximate this effect by comparing the property to a value that you are sure does not exist. e.g. if ex:estimate is always non-negative, then ex:estimate > -1 would return resource that had any value for ex:estimate. Regards, ___________________________________________________________________________ Arthur Ryman DE, Chief Architect, Reporting & Portfolio Strategy and Management IBM Software, Rational Toronto Lab | +1-905-413-3077 (office) | +1-416-939-5063 (mobile) From: Joe Ross <[email protected]> To: [email protected] Date: 07/12/2012 06:39 PM Subject: [oslc-core] missing oslc query functionality Sent by: [email protected] We've had a couple of scenarios that don't seem to be addressable using the OSLC core 2.0 query syntax: 1. Finding all resources that don't have a particular value for a property. The != operator won't work for this, because in the case of multi-valued properties, records will be returned as long as there is a value that is not equal, even if there is also a value that is equal. This would require a unary "not" logical operator. 2. Finding all resources that have any value for a particular property (matching on predicate, regardless of value). This is probably would probably be best handled by a unary "exists" operator, or support for wildcard as the value in oslc.where clauses. Currently the grammar seems to only allow for wildcard for the predicate. So, am I correct in this assessment? If so, was this omission intentional (and if so what was the reason), or an oversight? ================================================ Joe Ross/Austin/IBM, [email protected] Tivoli Autonomic Computing & Component Technologies 512-286-8311, T/L 363-8311_______________________________________________ Oslc-Core mailing list [email protected] http://open-services.net/mailman/listinfo/oslc-core_open-services.net
