# SPARQL Rule with reasoning does not work **URL:** \ **Category:** Support\ **Created:** [August 21, 2017, 4:27pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519 "2017-08-21T16:27:28Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![arsham](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@arsham](https://community.stardog.com/u/arsham)\ **Post date:** [August 21, 2017, 4:27pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/1 "2017-08-21T16:27:29Z")
Hello All, I am a newbie to Stardog DB and try to use the Rule and the reasoning feature of Stardog. I expect from enabling the reasoning and using the following simple rule to update values of individuals matching to the IF condition. It does happening. I will truly appreciate if you can help me. Here is the simple rule that tries to update the state of a ?x based on the state of another object ?p. I added the rule to the database and the web interface for database browsing shows it as a SPARQLRule. I also enabled reasoning and chose the SL reasoning algorithm. ```auto IF { ?x a :Path. ?x :hasActive ?p. ?p :hasState ?s. BIND ( ?s AS ?state). } THEN { ?x :hasState ?state . } ``` Thanks in advance! ---
**Author:** ![jess](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/jess/32/10_2.png) [@jess](https://community.stardog.com/u/jess)\ **Post date:** [August 21, 2017, 4:45pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/2 "2017-08-21T16:45:08Z")
Hi, Please share the query you are executing, the expected results and the actual results. Jess ---
**Author:** ![arsham](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@arsham](https://community.stardog.com/u/arsham)\ **Post date:** [August 21, 2017, 7:17pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/3 "2017-08-21T19:17:29Z")
Hi Jess, Thanks for your reply, I am not running any query, I am under the impression of this rule will fire whenever any changes in the db are happening and I expect it updates the `?X` state with the state of `?P`. To test if it works, I simply change the state of the `?P` to “Inactive” and expect `?X :hasState "active"` changes to `?X :hasState "Inactive"` automaticlly. BR, ---
**Author:** ![stephen](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/stephen/32/27_2.png) [@stephen](https://community.stardog.com/u/stephen)\ **Post date:** [August 21, 2017, 7:24pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/4 "2017-08-21T19:24:17Z")
Hi, It sounds like you are expecting the rules to materialize triples and act as sort of a "trigger." Stardog does not perform materialization; we perform [Query Rewriting](https://www.stardog.com/docs/#_query_rewriting) at query runtime. In short, If you run the query `select * where {?x :hasState "active"}`, it will give you all of the entities that either explicitly have that triple in the db, or for which the rule applies. Instead of looking for `?X :hasState "Inactive"` in the database, try running the query above, changing a state, and running it again. You should see the results you're looking for. ---
**Author:** ![arsham](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@arsham](https://community.stardog.com/u/arsham)\ **Post date:** [August 22, 2017, 1:11pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/5 "2017-08-22T13:11:58Z")
Hi, Thanks for your reply, I can see the expected results by running the query (1): select \* where {?x :hasState “Inactive”}, however, if I run the select \* where {?x :hasState “active”} query it also returns the triples supposed to be “Inactive” ! I guess this time it is because of it has explicit value of “active” . It is a preplex behaviour to me, is there anyway that I can get more consistent outputs? Thanks ! ---
**Author:** ![lorenz\_b](https://avatars.discourse-cdn.com/v4/letter/l/d78d45/32.png) [@lorenz\_b](https://community.stardog.com/u/lorenz_b)\ **Post date:** [August 23, 2017, 7:58am UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/6 "2017-08-23T07:58:37Z")
The rule does exactly what’s stated there. It matches the data and produces new data. If a path has both states, indeed this will be inferred. But to be honest, without seeing the data it’s impossible to help you further. Can you share the sample data please? ---
**Author:** ![arsham](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@arsham](https://community.stardog.com/u/arsham)\ **Post date:** [August 23, 2017, 2:22pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/7 "2017-08-23T14:22:55Z")
Thanks for your reply, You can find a simplified data set from [test-arsham-w-const-2-1.ttl](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/1X/0d81c018bc8405d5ba5159d32e821fc1f05e23cb.ttl) (2.3 KB) For this data set, if I run the query: `SELECT * WHERE {?p a of:Path; of:hasState 'Inactive'}` returns Nil if the reasoning is OFF and return the three paths if the reasoning is ON as it should be. However, If I run `SELECT * WHERE {?p a of:Path; of:hasState 'active'}` it always (with/without reasoning) return the same three defined paths. If I change the rule to the one mentioned in the previous post, it did not work at all. I have to specify the value for the Dataproperty :hasState to make it work as described. Many Thanks for help! ---
**Author:** ![stephen](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/stephen/32/27_2.png) [@stephen](https://community.stardog.com/u/stephen)\ **Post date:** [August 24, 2017, 1:31pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/8 "2017-08-24T13:31:05Z")
Hi, With your dataset I was able to play around with the rules/queries and _sort of_ get what I think you’re looking for. I removed ALL of the `of:hasState` triples from the `of:Path`s, keeping them just on the `of:AvailPath`s. I then added the following rule: ```auto [] a ; """IF { ?x a of:Path. ?x of:hasActive/of:hasState \"active\". } THEN { ?x of:hasState \"active\". }""" . ``` This allows me to query the “active” Paths like so: ```auto > stardog query -r myDb "select ?p {?p a of:Path ; of:hasState \"active\"}" +---------------------------------------------+ | p | +---------------------------------------------+ | of:path_00:00:00:00:00:01_00:00:00:00:00:03 | +---------------------------------------------+ ``` And the “Inactive” Paths like so: ```auto > stardog query -r myDb "select ?p {?p a of:Path . MINUS {?p of:hasState \"active\"}}" +---------------------------------------------+ | p | +---------------------------------------------+ | of:path_00:00:00:00:00:01_00:00:00:00:00:04 | | of:path_00:00:00:00:00:01_00:00:00:00:00:02 | +---------------------------------------------+ ``` While it doesn’t reason out an “Inactive” triple, it does honor the logic of showing you `of:Path`s that are NOT “active” ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [September 7, 2017, 1:31pm UTC](https://community.stardog.com/t/sparql-rule-with-reasoning-does-not-work/519/9 "2017-09-07T13:31:36Z")
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