How to Dynamically Insert GUIDs into FetchXML Queries in C# and JavaScript

 When working with Microsoft Dynamics 365 CRM, FetchXML provides a robust mechanism for querying and retrieving data. A common requirement is to filter records based on specific GUIDs, which represent unique identifiers for records. In this article, we explore how to dynamically insert GUIDs into FetchXML queries using C# and JavaScript, ensuring that your queries can be adapted to various data retrieval scenarios efficiently.

Using returnId in FetchXML with C#

In C#, you might often find yourself needing to construct a FetchXML query dynamically and pass it to the CRM service to retrieve data. Here's how you can include a returnId in your FetchXML query string:

Step 1: Construct the FetchXML String

First, you need to construct your FetchXML string. Ensure you're leaving placeholders for the returnId that you will replace dynamically. Here's an example of how to construct such a string in C#:

Guid returnId = // Assume this is obtained at runtime

string fetchXml = $@"

<fetch aggregate='true'>

    <entity name='new_returnproduct'>

        <attribute name='new_qtytoreturn' alias='totalquantitytoreturn' aggregate='sum' />

        <attribute name='new_returnproductid' alias='totalcountreturnproduct' aggregate='count' />

        <filter>

            <condition attribute='new_return' operator='eq' value='{returnId.ToString("D")}' />

        </filter>

    </entity>

</fetch>";

Step 2: Replace the Placeholder with Actual returnId

In the above template, the returnId is dynamically inserted into the FetchXML string using string interpolation marked by $"...". returnId.ToString("D") formats the GUID to its string representation without any additional characters.

Using returnId in FetchXML with JavaScript

In JavaScript, especially when working within Dynamics 365 forms or web resources, you might need to dynamically construct and use FetchXML queries. Below is how you can incorporate a returnId dynamically:

Step 1: Prepare Your FetchXML Template

You need to create a template for your FetchXML query, similar to the C# method but adapted for JavaScript's template literals:

var returnId = "your-guid-here"; // This should be set to the actual GUID you want to use

var fetchXml = `

<fetch aggregate="true">

    <entity name="new_returnproduct">

        <attribute name="new_qtytoreturn" alias="totalquantitytoreturn" aggregate="sum" />

        <attribute name="new_returnproductid" alias="totalcountreturnproduct" aggregate="count" />

        <filter>

            <condition attribute="new_return" operator="eq" value="${returnId}" />

        </filter>

    </entity>

</fetch>`;

Step 2: Inject the returnId into the Query

In this example, the returnId is directly embedded into the FetchXML string using JavaScript's template literals, denoted by backticks (). This allows for easy insertion of variables like returnId`.

Conclusion

Using returnId in FetchXML queries is essential for filtering and retrieving specific data sets in Dynamics 365. Whether you are coding in C# or JavaScript, the process involves dynamically constructing the FetchXML string to include the returnId based on your application's needs. This ensures your queries are both flexible and precise, allowing you to interact effectively with Dynamics 365 CRM data.