Creating and removing N:N relationships between Dataverse records using JavaScript and Power Pages Web API

Managing Dataverse N:N relationships between records using the Power Pages Web API can be trickier as there are few samples around and the syntax differs a little bit from handling N:N relationships using the Dataverse Web API.

In this post I will show a quick code sample on how you can handle that, using a sample N:N custom relationship between Contacts and Accounts.

Prerequisites

• All required fields (including the N:N relationship name) in the code must be enabled for the WebAPI for the Power Pages site where you wish to run the code creation via Web API
• The WebAPI Wrapper code must be added to the page you are using the JavaScript code
• An N:N relationship between Contact and Account needs to be configured in Dataverse (out of the box a Contact can have only one Account associated, but with this custom relationship we can assign to more)

Associating a Contact with an Account in an N:N relationship

You can use the following JavaScript function to Associate a Contact with an Account in an N:N relationship (replace your_Relationship_Schema_Name by your relationship schema name):

function AssociateRecords(contactId, accountId) {    
        var parentRecord = {
            "@odata.id": `https://${location.host}/_api/accounts(${accountId})`
        };
        webapi.safeAjax({
            type: "POST",
            contentType: "application/json",
            url: `/_api/contacts(${contactId})/your_Relationship_Schema_Name/$ref`,
            data: JSON.stringify(parentRecord),
            success: function (data, textStatus, xhr) {
                console.log("success");
                console.log(xhr.getResponseHeader("entityid"));                
            },
            error: function (xhr, textStatus, errorThrown) {
                console.log("error");
                console.log(xhr);              
            }
        });    
}

This function takes two arguments: contactId and accountId. It creates an object named parentRecord with the property @odata.id that contains a URL pointing to an account record with the given accountId.

Then the function uses the Power Pages Web API to run a POST request with this object into the contact object to create a new reference a for the custom relationship.

Disassociating a Contact with an Account in an N:N relationship

You can use the following JavaScript function to Disassociate a Contact from an Account in an N:N relationship (replace your_Relationship_Schema_Name by your relationship schema name):

function DisassociateRecords(contactId, accountId) {
    webapi.safeAjax({
        type: "DELETE",
        contentType: "application/json",
        url: `/_api/contacts(${contactId})/your_Relationship_Schema_Name(${accountId})/$ref`,
        success: function (data, textStatus, xhr) {
            console.log("success");
            console.log(xhr.getResponseHeader("entityid"));
        },
        error: function (xhr, textStatus, errorThrown) {
            console.log("error");
            console.log(xhr);
        }  
    });
}

This function uses the Power Pages Web API to run a DELETE request with the URL pointing to an account record with the given accountid and the related contactid relationship reference.

References

How to: Use Portal Web API – Microsoft Learn

Associate and disassociate tables by using the Web API