每个都有两个集合

Question

如何在mule中的foreach范围内指定两个集合变量？

<foreach collection="#[flowVars.ar] && #[flowVars.md]" doc:name="For Each" counterVariableName="i">
    <db:select config-ref="Generic_Database_Configuration" doc:name="Database">
        <db:parameterized-query><![CDATA[SELECT a.tempocode AS tempocode 
        FROM Referencelookup a WITH (NOLOCK)
        JOIN ReferenceLookup r WITH (NOLOCK) ON r.Metadatatype = 'ServicerCode' AND r.TempoCode = a.AccountName
        WHERE a.metadatatype =#[flowVars.md[counter-1]]
        AND a.lookuptype = 'fiserv' AND r.refcode =#[flowVars.srvcode] AND a.refcode =#[flowVars.ar[counter-1]]]]></db:parameterized-query>
    </db:select>
    <logger message="#[payload]" level="INFO" doc:name="Logger"/>
</foreach>