WSO2 Data Service, Enterprise Integrator and Data Mapper mediator

Question

I have created a Data Service (DS) and expose the data as a REST resource. and I could successfully retrieve data via CURL command given below.

curl -X GET -H "Accept: application/json" http://localhost:8280/services/TestDataService.HTTPEndpoint/Member/0

The REST API resource template is Member/{MemberID} - DS Endpoint

The response is,

{"Members":{"Email":"[email protected]","FirstName":"Mad","MembershipCategory":"Gold","InsuranceType":"Health","LastName":"Tim"}}

---

Then I wanted to convert this JSON response to a CSV using WSO2 EI's Data Mapper mediator. I know there are alternative ways to achieve this usecase via other mediators or WSO2 API manager.

I created another API resource in WSO2 EI which has the template

/convertDetails/Member/{MemberID} - EI Endpoint

Anyhow, with following configurations, I could not get the correct response when I call the REST API resource from a REST client.

Following is my mediation flow,

<?xml version="1.0" encoding="UTF-8"?>
<api context="/convertDetails" name="MemberDetailsConversion" xmlns="http://ws.apache.org/ns/synapse">
    <resource methods="GET" uri-template="/Member/{MemberID}">
        <inSequence>
            <log description="Request Log" level="full"/>
            <send>
                <endpoint>
                    <http method="get" uri-template="http://localhost:8280/services/TestDataService.HTTPEndpoint/Member/{uri.var.MemberID}"/>
                </endpoint>
            </send>
        </inSequence>
        <outSequence>
            <datamapper config="gov:datamapper/MemberDetailsMapping.dmc" inputSchema="gov:datamapper/MemberDetailsMapping_inputSchema.json" inputType="JSON" outputSchema="gov:datamapper/MemberDetailsMapping_outputSchema.json" outputType="CSV"/>
            <log description="Response Log" level="full"/>
            <respond/>
        </outSequence>
        <faultSequence/>
    </resource>
</api>

But still when I invoke the EI REST resource endpoint, http://localhost:8280/convertDetails/Member/0, it give me an ERROR.I have extracted the first few lines of the stack below.

[2018-11-01 10:30:30,817] [EI-Core] ERROR - DBInOutMessageReceiver Error in in-out message receiver
DS Code: INCOMPATIBLE_PARAMETERS_ERROR
Nested Exception:-
javax.xml.stream.XMLStreamException: DS Fault Message: Error in 'CallQuery.extractParams', cannot find parameter with type:query-param name:MemberID
DS Code: INCOMPATIBLE_PARAMETERS_ERROR
Source Data Service:-
Name: TestDataService
Location: /Users/mad/Documents/wso2ei-6.3.0/wso2/tmp/carbonapps/-1234/1541088489969TestDataServiceProjectCompositeApplication_1.0.0.car/TestDataService_1.0.0/TestDataService-1.0.0.dbs
Description: N/A
Default Namespace: http://ws.wso2.org/dataservice
Current Request Name: _getmember_memberid
Current Params: {}

I'm assuming that I have missed something along the configuration. Would appreciate your help regarding this.