SELECT cpe.sku AS Sku, GROUP_CONCAT(ccp.category_id) AS Category_Ids
FROM catalog_product_entity cpe
JOIN catalog_category_product ccp ON cpe.entity_id = ccp.product_id
GROUP BY cpe.sku
INTO OUTFILE '/var/lib/mysql-files/orders.csv'
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n';