How to get Data Service query to return type other than String?

I have set up a data service to call a stored procedure which returns 4 columns. An int, a string and 2 longs.

   <query id="sp_GetDisallowedComponents" useConfig="DB">
        <sql>EXEC dbo.GetDisallowedComponents </sql>
        <result element="DisallowedData" rowName="DisallowedDataRow">
            <element name="ID" column="ID"/>
            <element name="ComponentName" column="ComponentName"/>
            <element name="MinVersion" column="MinVersion"/>
            <element name="MaxVersion" column="MaxVersion"/>
        </result>
    </query>

The problem is that these columns are always string in the generated WSDL.

<xs:complexType name="DisallowedDataRow">
<xs:sequence>
<xs:element minOccurs="0" name="ID" nillable="true" type="xs:string"/>
<xs:element minOccurs="0" name="ComponentName" nillable="true" type="xs:string"/>
<xs:element minOccurs="0" name="MinVersion" nillable="true" type="xs:string"/>
<xs:element minOccurs="0" name="MaxVersion" nillable="true" type="xs:string"/>
</xs:sequence>
</xs:complexType>

Is there a way of specifying the types of the columns?

Steve