End Google Ads 201810 - BS.net 01 --> i have many payment rows in same date and i want to count how many payments i this date and put count result in new 1 row

i'm made it manually by excel but i want make it in c# with SQL Server & Data Grid View

this 2 photos make you understand
https://i.stack.imgur.com/mWj1M.png
https://i.stack.imgur.com/UhOzB.png