I want to add custom entity type export in system -> export

Question

I want to create custom entity export which export data from inventory_source with custom product attribute like color, size

I have referred this and this link and created my export model file and its working fine but when i join collection with catelog_product or its eav table its give error

Below is my code

1. Vendor/Module/etc/export.xml

   <?xml version="1.0"?>
   <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_ImportExport:etc/export.xsd">
       <entity name="custmom_stock_source" label="custom stock source" model="Vendor\Module\Model\Export\Sources" entityAttributeFilterType="custmom_stock_source"/>
   </config>
   

2. Vendor/Module/Model/Export/Source.php

       <?php
       namespace Vendor\Module\Model\Export;
   
   
       use Exception;
       use Magento\Framework\App\Config\ScopeConfigInterface;
           use Magento\ImportExport\Model\Export\Factory as ExportFactory;
           use Magento\ImportExport\Model\Export\AbstractEntity;
           use Magento\Inventory\Model\ResourceModel\SourceItem;
           use Magento\Inventory\Model\ResourceModel\SourceItem\Collection as SourceItemCollection;
           use Magento\InventoryImportExport\Model\Export\SourceItemCollectionFactoryInterface;
           use Magento\InventoryImportExport\Model\Export\ColumnProviderInterface;
           use Magento\Store\Model\StoreManagerInterface;
           use Magento\ImportExport\Model\ResourceModel\CollectionByPagesIteratorFactory;
   
           use Vendor\Module\Model\Export\AttributeCollectionProvider;
           use \Magento\Store\Model\Store;
   
          class Sources extends \Magento\ImportExport\Model\Export\AbstractEntity
          {
   
   
       /**
        * @var AttributeCollectionProvider
        */
       private $attributeCollectionProvider;
   
       /**
        * @var SourceItemCollectionFactoryInterface
        */
       private $sourceItemCollectionFactory;
   
       /**
        * @var ColumnProviderInterface
        */
       private $columnProvider;
   
       /**
        * Product collection
        *
        * @var \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory
        */
       protected $_entityCollectionFactory;
   
        /**
        * Product collection
        *
        * @var \Magento\Catalog\Model\ResourceModel\Product\Collection
        */
       protected $_entityCollection;
   
       /**
        * @param ScopeConfigInterface $scopeConfig
        * @param StoreManagerInterface $storeManager
        * @param ExportFactory $collectionFactory
        * @param CollectionByPagesIteratorFactory $resourceColFactory
        * @param AttributeCollectionProvider $attributeCollectionProvider
        * @param SourceItemCollectionFactoryInterface $sourceItemCollectionFactory
        * @param ColumnProviderInterface $columnProvider
        * @param array $data
        */
       public function __construct(
       ScopeConfigInterface $scopeConfig,
       StoreManagerInterface $storeManager,
       ExportFactory $collectionFactory,
       CollectionByPagesIteratorFactory $resourceColFactory,
       AttributeCollectionProvider $attributeCollectionProvider,
       SourceItemCollectionFactoryInterface $sourceItemCollectionFactory,
       \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productcollectionFactory,
       ColumnProviderInterface $columnProvider,
       array $data = []
       ) {
       $this->_entityCollectionFactory = $productcollectionFactory;
       $this->attributeCollectionProvider = $attributeCollectionProvider;
       $this->sourceItemCollectionFactory = $sourceItemCollectionFactory;
       $this->columnProvider = $columnProvider;
       parent::__construct($scopeConfig, $storeManager, $collectionFactory, $resourceColFactory, $data);
       }
   
       /**
        * @inheritdoc
        * @throws \Exception
        */
       public function getAttributeCollection()
       {
       return $this->attributeCollectionProvider->get();
       }
   
       /**
        * @inheritdoc
        * @throws Exception 
        */
       public function export()
       {
   
   
       $writer = $this->getWriter();
       $writer->setHeaderCols($this->_getHeaderColumns());
   
       /** @var SourceItemCollection $collection */
       $collection = $this->sourceItemCollectionFactory->create(
           $this->getAttributeCollection(),
           $this->_parameters
       );
   
       $productCollection = $this->_addProductCollection($collection);
       $entityCollection = $this->_getEntityCollection(true);
           $entityCollection->setOrder('entity_id', 'asc');
           $entityCollection->setStoreId(Store::DEFAULT_STORE_ID);
   
   
   
       foreach ($productCollection->getData() as $data) {
   
           unset($data[SourceItem::ID_FIELD_NAME]);
            unset($data['name']);
           $writer->writeRow($data);
       }
   
       return $writer->getContents();
       }
   
       public function _addProductCollection($collection)
       {
   
        $collection->getSelect()->joinLeft(
           ['catalog_product' => 'catalog_product_entity'],
           '(main_table.sku = catalog_product.sku)',
           [
           'catalog_product.entity_id',
           'catalog_product.attribute_set_id',
           ]
       );
   
       return $collection;
       }
   
       /**
        * @inheritdoc
        * @throws Exception
        */
       protected function _getHeaderColumns()
       {
       return $this->columnProvider->getHeaders($this->getAttributeCollection(), $this->_parameters);
       }
   
       /**
        * @inheritdoc
        * @SuppressWarnings(PHPMD.UnusedFormalParameter)
        */
       public function exportItem($item)
       {
       // will not implement this method as it is legacy interface
       }
   
       public function getEntityTypeCode()
       {
       return  'custmom_stock_source';
       }
   
      /* protected function _getEntityCollection()
       {
       // TODO: Implement _getEntityCollection() method.
       }*/
   
   
       /**
        * Get entity collection
        *
        * @param bool $resetCollection
        * @return \Magento\Framework\Data\Collection\AbstractDb
        */
       protected function _getEntityCollection($resetCollection = false)
       {
       if ($resetCollection || empty($this->_entityCollection)) {
           $this->_entityCollection = $this->_entityCollectionFactory->create();
       }
       return $this->_entityCollection;
       }
   
   }
   

3. Vendor/Module/Model/Export/AttributeCollectionProvider.php

     <?php
   
    declare(strict_types=1);
   
    namespace Vendor\Module\Model\Export;
   
    use Magento\Eav\Model\Entity\AttributeFactory;
    use Magento\Framework\Data\Collection;
    use Magento\ImportExport\Model\Export\Factory as CollectionFactory;
    use Magento\InventoryApi\Api\Data\SourceItemInterface;
    use Magento\InventoryImportExport\Model\Export\Source\StockStatus;
   
    /**
     * @api 
     */
    class AttributeCollectionProvider
    {
        /**
         * @var Collection
         */
        private $collection;
   
        /**
         * @var AttributeFactory
         */
        private $attributeFactory;
   
        /**
         * @param CollectionFactory $collectionFactory
         * @param AttributeFactory $attributeFactory
         * @throws \InvalidArgumentException
         */
        public function __construct(
        CollectionFactory $collectionFactory,
        AttributeFactory $attributeFactory
        ) {
        $this->collection = $collectionFactory->create(Collection::class);
        $this->attributeFactory = $attributeFactory;
        }
   
        /**
         * @return Collection
         * @throws \Exception
         */
        public function get(): Collection
        {
        if (count($this->collection) === 0) {
            /** @var \Magento\Eav\Model\Entity\Attribute $sourceCodeAttribute */
            $sourceCodeAttribute = $this->attributeFactory->create();
            $sourceCodeAttribute->setId(SourceItemInterface::SOURCE_CODE);
            $sourceCodeAttribute->setDefaultFrontendLabel(SourceItemInterface::SOURCE_CODE);
            $sourceCodeAttribute->setAttributeCode(SourceItemInterface::SOURCE_CODE);
            $sourceCodeAttribute->setBackendType('varchar');
            $this->collection->addItem($sourceCodeAttribute);
   
            /** @var \Magento\Eav\Model\Entity\Attribute $skuAttribute */
            $skuAttribute = $this->attributeFactory->create();
            $skuAttribute->setId(SourceItemInterface::SKU);
            $skuAttribute->setBackendType('varchar');
            $skuAttribute->setDefaultFrontendLabel(SourceItemInterface::SKU);
            $skuAttribute->setAttributeCode(SourceItemInterface::SKU);
            $this->collection->addItem($skuAttribute);
   
            /** @var \Magento\Eav\Model\Entity\Attribute $statusIdAttribute */
            $statusIdAttribute = $this->attributeFactory->create();
            $statusIdAttribute->setId(SourceItemInterface::STATUS);
            $statusIdAttribute->setDefaultFrontendLabel(SourceItemInterface::STATUS);
            $statusIdAttribute->setAttributeCode(SourceItemInterface::STATUS);
            $statusIdAttribute->setBackendType('int');
            $statusIdAttribute->setFrontendInput('select');
            $statusIdAttribute->setSourceModel(StockStatus::class);
            $this->collection->addItem($statusIdAttribute);
   
            /** @var \Magento\Eav\Model\Entity\Attribute $quantityAttribute */
            $quantityAttribute = $this->attributeFactory->create();
            $quantityAttribute->setId(SourceItemInterface::QUANTITY);
            $quantityAttribute->setBackendType('decimal');
            $quantityAttribute->setDefaultFrontendLabel(SourceItemInterface::QUANTITY);
            $quantityAttribute->setAttributeCode(SourceItemInterface::QUANTITY);
            $this->collection->addItem($quantityAttribute);
   
            /** @var \Magento\Eav\Model\Entity\Attribute $quantityAttribute */
            $productnameAttribute = $this->attributeFactory->create();
            $productnameAttribute->setId('name');
            $productnameAttribute->setBackendType('varchar');
            $productnameAttribute->setDefaultFrontendLabel('name');
            $productnameAttribute->setAttributeCode('name');
            $this->collection->addItem($productnameAttribute);
   
        }
   
        return $this->collection;
        }
    }
   

I am getting below error

 main.CRITICAL: Message has been rejected: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'main_table.name' in 'field list', query was: SELECT `main_table`.`source_item_id`, `main_table`.`source_code`, `main_table`.`sku`, `main_table`.`status`, `main_table`.`quantity`, `main_table`.`name`, `catalog_product`.`entity_id`, `catalog_product`.`attribute_set_id` FROM `inventory_source_item` AS `main_table`LEFT JOIN `catalog_product_entity` AS `catalog_product` ON (main_table.sku = catalog_product.sku) [] []

So export writer export data only from main table it is not using join table.

Kindly help.

Thanks Amit