Pass multiple values to target server for same querystring identifier

Google Cloud Apigee
1

I’m proxying to a backend that’s expecting, for example: http://example.com/endpoint?field=id&field=description

I’m trying to set these querystrings in an AssignMessage policy, but only the last one that I set is being reflected. Does apigee support assigning multiple QueryParams with the same key? This is the policy I’m using:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<AssignMessage async="false" continueOnError="false" enabled="true" name="Filter-displayed-fields">
    <DisplayName>Filter displayed fields</DisplayName>
    <Properties/>
    <Add>
        <QueryParams>
            <QueryParam name="field">id</QueryParam>
            <QueryParam name="field">description</QueryParam>
            <QueryParam name="field">status</QueryParam>
        </QueryParams>
    </Add>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo createNew="false" transport="http" type="request"/>
</AssignMessage>

But the resulting curl (through the trace tool looks like:

[https://<snip>?field=status](https://<snip>?field=status)
2

@Zach Tibbitts

The assign message policy in Apigee works using the key value pair mechanism. So if you use the same query param name to set multiple values, it will overwrite the first one.

The same behavior will also be replicated in javascript policy if you set the values to the flow variable request.queryparam.field

I can suggest that you try string concatenation in javascript policy to achieve this.