Resolved Magento adding a tax class to all products using mysql

First you need to run below query

SELECT attribute_id FROM eav_attribute WHERE attribute_code = 'tax_class_id'

then get attribute id example attribute_id  '121'

SELECT *
FROM `catalog_product_entity_int`
WHERE `attribute_id` =121

the update `catalog_product_entity_int` your tax id like 1 or 2 based on attribute_id

  UPDATE `catalog_product_entity_int` SET value=2 WHERE `attribute_id`='121'