XrmServiceToolkit.Soap.Fetch

// 関連付けエンティティデータ存在チェック
var emailFlg = false;
var getInfo =
    "<fetch>" +
    "<entity name='new_entity1'>" +
    "<filter>" +
    "<condition attribute='new_field1' operator='eq' value='" + offer.new_hospitalname.Id + "' />" +
    "<condition attribute='new_field2' operator='eq' value='1' />" +
    "<condition attribute='new_field3' operator='eq' value='1' />" +
    "<condition attribute='statecode' operator='eq' value='0' />" +
    "<condition attribute='new_entity2●' operator='not-null' />" +   //lookup
    "<condition attribute='new_field5' operator='not-null' />" +
    "</filter>" +
    "<link-entity name='new_entity2' from='new_entity2id' to='new_entity2●'>" +
    "<attribute name='new_field11' />" +
    "<filter>" +
    "<condition attribute='new_field22' operator='eq' value='0' />" +
    "<condition attribute='statecode' operator='eq' value='0' />" +
    "<condition attribute='new_field33id' operator='not-null' />" +
    "</filter>" +
    "</link-entity>" +
    "</entity>" +
    "</fetch>";

var resultList = XrmServiceToolkit.Soap.Fetch(getInfo);
if (resultList.length > 0) {
    // メール送信ダイアログの表示
    if (window.confirm("宛先に送信しますか？")) emailFlg = true;
}