SNO,DESTNO,RATE
1,91,45
2,914373,97
3,9144,79
4,1,34
5,14,4
6,23,12


when i supply,

DESTNO  i need to get the best match and a single value,

91         -> 91
914492345  -> 9144
9143732323 -> 914373
914372     -> 91
14         -> 1

How to form the sql query for the above to get the best and only single  value?