# APOC.PERIODIC.ITERATE Dynamic list iteration java/Spring

**URL:** <https://community.neo4j.com/t/apoc-periodic-iterate-dynamic-list-iteration-java-spring/4806>\
**Category:** Cypher\
**Tags:** apoc, neo4j-driver, java-api\
**Created:** [February 2, 2019, 5:00am UTC](https://community.neo4j.com/t/apoc-periodic-iterate-dynamic-list-iteration-java-spring/4806 "2019-02-02T05:00:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sankar.mathivanan](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/sankar.mathivanan/32/2815_2.png) [@sankar.mathivanan](https://community.neo4j.com/u/sankar.mathivanan)\
**Post date:** [February 2, 2019, 5:00am UTC](https://community.neo4j.com/t/apoc-periodic-iterate-dynamic-list-iteration-java-spring/4806/1 "2019-02-02T05:00:28Z")

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1. I want to pass the list that needs to be iterated and create nodes and relationships out of it.
2. I am using Apoc.periodic.iterate now because previously i have tried with unwind which caused deadlock due to parallel execution.
3. Help me to fix the current code section.
4. I am processing more than 900k data in chunks. Which i will read it from kafka topics.

` @Query("CALL apoc.periodic.iterate("+"""
+ " UNWIND $items as item return item" ,"
+ ""MERGE (src:Item {name: item.name}) "
+ " ON CREATE SET src.name = item.name, "
+ " src.updateDate = {processDate} "
+ "MERGE (dest:ItemDet {upc: item.upc}) "
+ " ON CREATE SET dest.upc = item.upc, "
+ " dest.creationDate = {processDate} " )",
{batchSize:1000, parallel:false,iterateList:true,params:{items:{items}}})")
Result mergeItems(@Param("items") List<?> items,
@Param("processDate") String processDate); `

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<div class="post-metadata">

**Author:** ![michael.hunger](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/michael.hunger/32/27377_2.png) [@michael.hunger](https://community.neo4j.com/u/michael.hunger)\
**Post date:** [February 3, 2019, 11:44pm UTC](https://community.neo4j.com/t/apoc-periodic-iterate-dynamic-list-iteration-java-spring/4806/2 "2019-02-03T23:44:50Z")

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You missed to pass in `processDate` as a parameter to the periodic.iterate.