SQL Query on finding highest within duplicates

Question

I am trying to write a SQL Query. If a duplicate SNO+SG Combination is found, we need to pick up the one having the highest value. If no duplicate value is found for a SNO+SG Combination, we will take that as it is. The sample input and output is over here:

Answer 1

Do you just want aggregation:

select bg, sno, sg, max(value)
from t
group by bg, sno, sg;