dblookup mediator not executed if it is placed after an iterate mediator - wso2-esb

Question

Does anyone know why a dblookup mediator is not executed if it is placed after an iterate mediator and both of these mediators are enclosed within a filter mediator? See my code snippet and corresponding log below. Thank you in advance.
<?xml version="1.0" encoding="UTF-8"?>
<sequence name="DownloadSeq" onError="AppDefaultFailSeq"
trace="disable" xmlns="http://ws.apache.org/ns/synapse">
<property name="OUT_ONLY" scope="default" type="STRING" value="true"/>
<dblookup description="DOWNLOAD FILES">
<connection>
<pool>
<dsName>jdbc/dsName</dsName>
</pool>
</connection>
<statement>
<sql><![CDATA[some sql query]]></sql>
<result column="id" name="fileId"/>
<result column="file_name_pattern" name="fileNamePattern"/>
<result column="uri" name="fileSource"/>
<result column="file_dest" name="fileDest"/>
</statement>
</dblookup>
<!-- CHECK TO SEE IF A RECORD IS RETURNED. EXIT IF NO RECORD RETURNED -->
<filter xpath="boolean(get-property('fileId'))">
<then>
<fileconnector.search>
<source>{$ctx:fileSource}</source>
<filePattern>{$ctx:fileNamePattern}</filePattern>
<recursiveSearch>False</recursiveSearch>
</fileconnector.search>
<log level="full"/>
<property name="sequence" scope="default" type="STRING" value="after-smooks"/>
<iterate expression="//ns:result/ns:file" xmlns:ns="http://org.wso2.esbconnectors.FileConnector">
<target>
<sequence>
<log level="full"/>
<property expression="//ns:file" name="fileName"
scope="default" type="STRING"/>
<!-- DOWNLOAD THE FILE -->
<fileconnector.move>
<source>{$ctx:fileSource}</source>
<destination>{$ctx:fileDest}</destination>
</fileconnector.move>
</sequence>
</target>
</iterate>
<!-- UPDATE STATUS AS 'P' -->
<dblookup description="Update status to P">
<connection>
<pool>
<dsName>jdbc/dsName</dsName>
</pool>
</connection>
<statement>
<sql><![CDATA[some SQL statement]]></sql>
<parameter expression="get-property('fileId')" type="INTEGER"/>
<parameter type="CHAR" value="P"/>
</statement>
</dblookup>
<drop/>
</then>
<else>
<drop/>
</else>
</filter>
</sequence>
From the log file:
TID: [-1234] [] [2016-10-03 10:48:00,848] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - Start : Class mediator {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:48:00,849] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - invoking : class org.wso2.carbon.connector.FileMove.mediate() {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:48:01,396] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - End : Class mediator {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:48:01,397] DEBUG {org.apache.synapse.mediators.base.SequenceMediator} - End : Sequence <anonymous> {org.apache.synapse.mediators.base.SequenceMediator}
However, if I placed the dblookup mediator within the iterator mediator, it works as expected. see corresponding logs below.
TID: [-1234] [] [2016-10-03 10:33:01,037] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - Start : Class mediator {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:33:01,038] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - invoking : class org.wso2.carbon.connector.FileMove.mediate() {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:33:01,525] DEBUG {org.apache.synapse.mediators.ext.ClassMediator} - End : Class mediator {org.apache.synapse.mediators.ext.ClassMediator}
TID: [-1234] [] [2016-10-03 10:33:01,526] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Start : DBLookup mediator {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,526] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Getting a connection from DataSource jdbc/dsName and preparing statement : SELECT update_file_status(?,?) {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,526] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Setting as parameter : 1 value : 16 as JDBC Type : 4(see java.sql.Types for valid types) {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,526] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Setting as parameter : 2 value : P as JDBC Type : 1(see java.sql.Types for valid types) {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,526] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Successfully prepared statement : SELECT update_file_status(?,?) against DataSource : jdbc/dsName {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,527] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - Processing the first row returned : SELECT update_file_status(?,?) {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,527] DEBUG {org.apache.synapse.mediators.db.DBLookupMediator} - End : DBLookup mediator {org.apache.synapse.mediators.db.DBLookupMediator}
TID: [-1234] [] [2016-10-03 10:33:01,528] DEBUG {org.apache.synapse.mediators.base.SequenceMediator} - End : Sequence <anonymous> {org.apache.synapse.mediators.base.SequenceMediator}

Answer 1

In iterate mediator, use attribute continueParent="true"