select pe.sku, prodname.value as name,
ifnull(price.value, fs.price) as price,
thumbnail.value as thumbnail
from fhs_catalog_product_entity pe
left join fahasa_stock fs on fs.sku = pe.sku
LEFT JOIN fhs_catalog_product_entity_varchar prodname ON pe.entity_id = prodname.entity_id AND prodname.attribute_id = 71
left join fhs_catalog_product_entity_decimal price ON pe.entity_id = price.entity_id and price.attribute_id = 75
LEFT JOIN fhs_catalog_product_entity_varchar thumbnail ON pe.entity_id = thumbnail.entity_id AND thumbnail.attribute_id = 87
where pe.sku = '8801237812402'

union

select sss.special_sku as sku, prodname.value as name,
price.value as price, thumbnail.value as thumbnail
from fahasa_special_stock_sku sss
left join fhs_catalog_product_entity pe on pe.sku = sss.special_sku
LEFT JOIN fhs_catalog_product_entity_varchar prodname ON pe.entity_id = prodname.entity_id AND prodname.attribute_id = 71
left join fhs_catalog_product_entity_decimal price ON pe.entity_id = price.entity_id and price.attribute_id = 75
LEFT JOIN fhs_catalog_product_entity_varchar thumbnail ON pe.entity_id = thumbnail.entity_id AND thumbnail.attribute_id = 87
where sss.sku = '8801237812402';