First of all , squeeze grated cucumber in bowl
Don't squeeze too much
You can use the squeezed water for other purpose
Now take curd and sugar in a bowl and mix it well
There should not be any lumps
Then add cucumber, cumin powder and black salt in the curd and mix it well
Place this raiyta in fridge for half an hour
Now your cool cool cucumber raiyta is ready to be served
Sprinkle some cumin powder before serving