# Creating triggers **URL:** \ **Category:** Neo4j Graph Platform\ **Tags:** apoc, cypher\ **Created:** [January 10, 2024, 5:31pm UTC](https://community.neo4j.com/t/creating-triggers/65715 "2024-01-10T17:31:17Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![jacob3](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/jacob3/32/29487_2.png) [@jacob3](https://community.neo4j.com/u/jacob3)\ **Post date:** [January 10, 2024, 5:31pm UTC](https://community.neo4j.com/t/creating-triggers/65715/1 "2024-01-10T17:31:17Z")
Hello, I am attempting to use an `apoc.trigger` in order to create a set of nodes after a node - with a specific label - is created. However, it doesn't seem to be working. I updated/added the `apoc.conf` with the appropriate statements to enable `apoc.trigger`. I'm able to use `apoc.trigger` functions including installing a trigger. BUT, it's still not working for some reason. When I create new nodes, the trigger is not activated. Any thoughts on what I may be missing? ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [January 10, 2024, 6:43pm UTC](https://community.neo4j.com/t/creating-triggers/65715/2 "2024-01-10T18:43:53Z")
@jacob3 Neo4j version? APOC version? Can you share the cypher used to create the trigger? ---
**Author:** ![jacob3](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/jacob3/32/29487_2.png) [@jacob3](https://community.neo4j.com/u/jacob3)\ **Post date:** [January 10, 2024, 7:29pm UTC](https://community.neo4j.com/t/creating-triggers/65715/3 "2024-01-10T19:29:06Z")
Neo4j Version: 5.11 enterprise APOC Version: 5.11 core ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [January 10, 2024, 7:57pm UTC](https://community.neo4j.com/t/creating-triggers/65715/4 "2024-01-10T19:57:31Z")
@jacob3 > [@dana\_canzano](#): > > Can you share the cypher used to create the trigger? or is that not possible? ---
**Author:** ![jacob3](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/jacob3/32/29487_2.png) [@jacob3](https://community.neo4j.com/u/jacob3)\ **Post date:** [January 10, 2024, 8:36pm UTC](https://community.neo4j.com/t/creating-triggers/65715/5 "2024-01-10T20:36:43Z")
Here is the cypher that creates the trigger (in the `system` database. I changed the node labels to remove info that I couldn't share. 🙂 ```auto CALL apoc.trigger.install( 'dev', 'create-class-new-user', "UNWIND $createdNodes AS n WHERE n:User AND NOT (n)-[:PREFERS]->(:School) CREATE (p:School) SET p.id = randomUUID(), p.isPrimary = true, p.createdAt = datetime(), p.modifiedAt = datetime() WITH p CREATE (d1:Department {name: 'Math'}) SET d1.id = randomUUID(), d1.createdAt = datetime(), d1.modifiedAt = datetime(), d1.isPrimary = false CREATE (p)-[:HAS_DEPARTMENT]->(d1) CREATE (d2:Department {name: 'Science'}) SET d2.id = randomUUID(), d2.createdAt = datetime(), d2.modifiedAt = datetime(), d2.isPrimary = false CREATE (p)-[:HAS_DEPARTMENT]->(d2) WITH d1, d2 CREATE (t:Category {name:'Monday'}) SET t.id = randomUUID(), t.createdAt = datetime(), t.modifiedAt = datetime() CREATE (d1)-[:PREFERS]->(t) CREATE (d2)-[:PREFERS]->(t) WITH d1, d2 CREATE (t:Category {name:'Tuesday'}) SET t.id = randomUUID(), t.createdAt = datetime(), t.modifiedAt = datetime() CREATE (d1)-[:PREFERS]->(t) CREATE (d2)-[:PREFERS]->(t) WITH d1, d2 CREATE (t:Category {name:'Wednesday'}) SET t.id = randomUUID(), t.createdAt = datetime(), t.modifiedAt = datetime() CREATE (d1)-[:PREFERS]->(t) CREATE (d2)-[:PREFERS]->(t) WITH d1, d2 CREATE (t:Category {name:'Thursday'}) SET t.id = randomUUID(), t.createdAt = datetime(), t.modifiedAt = datetime() CREATE (d2)-[:PREFERS]->(t) WITH d1, d2 CREATE (t:Category {name:'Friday'}) SET t.id = randomUUID(), t.createdAt = datetime(), t.modifiedAt = datetime() CREATE (d1)-[:PREFERS]->(t)", {phase:'afterAsync'}) ``` ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [January 10, 2024, 9:43pm UTC](https://community.neo4j.com/t/creating-triggers/65715/6 "2024-01-10T21:43:52Z")
@jacob3 have u tried with a simpler trigger definition as a means to debug. Given ```auto UNWIND $createdNodes AS n WHERE n:User AND NOT (n)-[:PREFERS]->(:School) CREATE (p:School) ``` are any :School nodes created? If you remove the `WHERE` clause are any :School nodes created? ---
**Author:** ![jacob3](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/jacob3/32/29487_2.png) [@jacob3](https://community.neo4j.com/u/jacob3)\ **Post date:** [January 11, 2024, 1:42am UTC](https://community.neo4j.com/t/creating-triggers/65715/7 "2024-01-11T01:42:58Z")
Removing the where clause doesn't seem to work either. Am I not allowed to create a new node in a trigger? ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [January 11, 2024, 10:51pm UTC](https://community.neo4j.com/t/creating-triggers/65715/8 "2024-01-11T22:51:36Z")
@jacob3 given the current issue and rather than building out a trigger with a lot of complexity, I decided to build out a very small test case. And with Neo4j 5.11.0 and ```auto ls -al plugins/ drwxr-xr-x 2 neo4j neo4j 4096 Jan 11 22:24 . drwxr-xr-x 15 neo4j neo4j 4096 Dec 5 11:22 .. -rw-r--r-- 1 neo4j neo4j 14495768 Jan 11 22:24 apoc-5.11.0-core.jar -rw-rw-r-- 1 neo4j neo4j 11137885 Dec 5 11:20 apoc-5.11.0-extended.jar -rw-r--r-- 1 neo4j neo4j 2217 Aug 8 07:47 README.txt ``` and apoc.conf defined as ```auto cat ../conf/apoc.conf apoc.trigger.enabled=true apoc.trigger.refresh=60000 ``` and then i defined trigger as follows ```auto @system> CALL apoc.trigger.install( 'neo4j', 'create-class-new-user', "UNWIND $createdNodes AS cN create(n:Result {nodes:id(cN)})",{}); ``` which does nothing more than for the nodes creates define a new node `:Result` and set its `nodes:` property to be the id of the node created. And thus ```auto @neo4j> match (n:Test) return n; +---+ | n | +---+ +---+ 0 rows ready to start consuming query after 96 ms, results consumed after another 3 ms @neo4j> match (n:Result) return n; +---+ | n | +---+ +---+ 0 rows ready to start consuming query after 3 ms, results consumed after another 3 ms @neo4j> unwind range(1,5) as x create (n:Test {id:x}); 0 rows ready to start consuming query after 8 ms, results consumed after another 0 ms Added 5 nodes, Set 5 properties, Added 5 labels @neo4j> match (n:Test) return n.id, id(n); +--------------+ | n.id | id(n) | +--------------+ | 1 | 10101 | | 2 | 10102 | | 3 | 10103 | | 4 | 10104 | | 5 | 10105 | +--------------+ 5 rows ready to start consuming query after 4 ms, results consumed after another 4 ms @neo4j> match (n:Result) return n order by n.nodes asc;; +--------------------------+ | n | +--------------------------+ | (:Result {nodes: 10101}) | | (:Result {nodes: 10102}) | | (:Result {nodes: 10103}) | | (:Result {nodes: 10104}) | | (:Result {nodes: 10105}) | +--------------------------+ 5 rows ready to start consuming query after 73 ms, results consumed after another 7 ms ``` so would seem to work for me. ---
**Author:** ![jacob3](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/jacob3/32/29487_2.png) [@jacob3](https://community.neo4j.com/u/jacob3)\ **Post date:** [January 11, 2024, 11:32pm UTC](https://community.neo4j.com/t/creating-triggers/65715/10 "2024-01-11T23:32:33Z")
Thanks @dana_canzano for looking into this. What worked for me was keeping the `phase` parameter undefined, i.e. `"CALL apoc.trigger.install("", "", {})"`. Now it's working! ---
**Author:** ![StuMoore](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/stumoore/32/29270_2.png) [@StuMoore](https://community.neo4j.com/u/StuMoore)\ **Post date:** [January 12, 2024, 4:54pm UTC](https://community.neo4j.com/t/creating-triggers/65715/11 "2024-01-12T16:54:38Z")
There is another option besides APOC, we have introduced Change Data Capture (CDC) in Neo4j, it is currently available as a beta in versions from Neo4j 5.14 Enterprise. You can create selectors which watch for specific labels, when a node is created a change event will be created and you can then use that to perform the desired action [Introduction - Change Data Capture](https://neo4j.com/docs/cdc/current/)