If you can generate guid and use it in deep insert, then you should be about to set both lookup fields. But this is not best pratice.
var accountId = "00000000-0000-0000-0000-000000000009"
var contactId = "00000000-0000-0000-0000-000000000010"
var record = {};
record = {
"accountid": accountId,
"name": "Sample Account",
"primarycontactid":
{
"firstname": "John",
"lastname": "Smith",
"contactid": contactId,
"parentcustomerid_account@odata.bind": "/accounts(" + accountId + ")"
}
}
var req = new XMLHttpRequest();
req.open("POST", Xrm.Utility.getGlobalContext().getClientUrl() + "/api/data/v9.2/accounts", true);
req.setRequestHeader("OData-MaxVersion", "4.0");
req.setRequestHeader("OData-Version", "4.0");
req.setRequestHeader("Content-Type", "application/json; charset=utf-8");
req.setRequestHeader("Accept", "application/json");
req.setRequestHeader("Prefer", "odata.include-annotations=*");
req.onreadystatechange = function () {
if (this.readyState === 4) {
req.onreadystatechange = null;
if (this.status === 204) {
var uri = req.getResponseHeader("OData-EntityId");
var regExp = /\(([^)]+)\)/;
var matches = regExp.exec(uri);
var newId = matches[1];
console.log(newId);
} else {
console.log(this.responseText);
}
}
};
req.send(JSON.stringify(record));
