Sort result in grid DESC order

Question

I'm using the sales_order collection. Now I was able to display it in my grid custom admin page. But I want the result to display in descending order. So meaning the latest order should be displayed at the top portion. But eventhough I added the sortOrder still no luck. Am I missing something? Below is my Grid code

entity_id asc 0 text ID text Customer Email

            </item>
        </argument>
    </column>
    <column name="customer_firstname">
       <argument name="data" xsi:type="array">
           <item name="config" xsi:type="array">
               <item name="filter" xsi:type="string">text</item>
               <item name="label" xsi:type="string" translate="true">First Name</item>

           </item>
       </argument>
    </column>
    <column name="customer_lastname">
       <argument name="data" xsi:type="array">
           <item name="config" xsi:type="array">
               <item name="filter" xsi:type="string">text</item>
               <item name="label" xsi:type="string" translate="true">Last Name</item>

           </item>
       </argument>
    </column>
    <column name="customer_middlename">
       <argument name="data" xsi:type="array">
           <item name="config" xsi:type="array">
               <item name="filter" xsi:type="string">text</item>
               <item name="label" xsi:type="string" translate="true">Middle Name</item>

           </item>
       </argument>
    </column>
    <column name="created_at" class="Magento\Ui\Component\Listing\Columns\Date" >
       <argument name="data" xsi:type="array">
           <item name="config" xsi:type="array">
               <item name="filter" xsi:type="string">dateRange</item>
               <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/date</item>
               <item name="dataType" xsi:type="string">date</item>
               <item name="label" xsi:type="string" translate="true">Order Date</item>
                <item name="sorting" xsi:type="string">desc</item>
                <item name="sortOrder" xsi:type="number">1</item>
           </item>
       </argument>
   </column>

I already cleared my cache and all but it's not taking effect. Also I want the Order Date be displayed at the very first column

Answer 1

Follow this link click here

change this Function

public function _beforeLoad()
{
    parent::_beforeLoad();
    $this->setOrder('your_column_name', 'DESC');
    return $this;
}