footer sum_total use value once

I´m using #sum_total in grids footer and its working fine but when i i get repeated values i want them count once (something like SUM(DISTINCT ´Column´) in MYSQL)Is there any way how can I set that #sum_total counts these column values once? Or do I need to do this elsewhere? ( -> and if yes then how do I get this value to footer)

thank you for reply

Unfortunately you will have to create a custom logic to calculate the sum.
You may use the setFooterLabel() method to set new value to the footer: … ooterlabel