//for Regular Price
UPDATE wp_postmeta 
SET meta_value = diff_price_value 
WHERE post_id = variation_id AND meta_key = '_regular_price';

//for Price
UPDATE wp_postmeta 
SET meta_value = price_value 
WHERE post_id = variation_id AND meta_key = '_price';

//for Sale Price
UPDATE wp_postmeta 
SET meta_value = price_value 
WHERE post_id = variation_id AND meta_key = '_sale_price';