Add custom columns to Order Grid in Admin Magento 2

We will learn how to add your custom columns to Order Grid in Admin without adding columns to sales_order_grid table in Database.

Firstly, we will create Order listing UI component instance. The original file for rendering the Product Grid is Magento_Catalog/view/adminhtml/ui_component/sales_order_grid.xml

Create a file with same name and path in your module.

app/code/[Vendor]/[Module_Name]/view/adminhtml/ui_component/sales_order_grid.xml

<?xml version="1.0" encoding="UTF-8"?>
<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
    <columns name="sales_order_columns">
        <column name="custom_column">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="visible" xsi:type="boolean">true</item>
                    <item name="filter" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Custom Column</item>
                </item>
            </argument>
        </column>
    </columns>
</listing>

Now, create a plugin for Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory

Doing this there will be no dependency on rewrites and it will make the lean.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">

    <type name="Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory">
        <plugin name="sales_order_additional_columns" type="[Vendor]\[Module_Name]\Plugin\SalesOrderCustomColumn" sortOrder="10" disabled="false" />
    </type>

</config>

Next step is to create the Plugin folder and Plugin class in the module.

app/code/[Vendor]/[Module_Name]/Plugin/SalesOrderCustomColumn.php

<?php 
namespace [Vendor]\[Module_Name]\Plugin;

use Magento\Framework\Message\ManagerInterface as MessageManager;
use Magento\Sales\Model\ResourceModel\Order\Grid\Collection as SalesOrderGridCollection;

class SalesOrderCustomColumn
{
    private $messageManager;
    private $collection;

    public function __construct(MessageManager $messageManager,
        SalesOrderGridCollection $collection
    ) {

        $this->messageManager = $messageManager;
        $this->collection = $collection;
    }

    public function aroundGetReport(
        \Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory $subject,
        \Closure $proceed,
        $requestName
    ) {
        $result = $proceed($requestName);
        if ($requestName == 'sales_order_grid_data_source') {
            if ($result instanceof $this->collection
            ) {
                $select = $this->collection->getSelect();
                $select->joinLeft(
                    ["secondTable" => $this->collection->getTable("table_name")],
                    'main_table.increment_id = secondTable.order_id',
                    array('custom_column')
                );                
                return $this->collection;
            }
        }
        return $result;
    }
}