Distinct Results from Solr Query

I have the solr indexed data as below ``` <doc> <str name="pincode">792056</str> <str name="city">Bijoypur-I Bl.I -III</str> <str name="district">Changlang</str> <str name="locality">Bijoypur-I Bl.I -III</str> <str name="state">Arunachal Pradesh</str> </doc> ``` My problem is for 10 distinct pincodes from the same state i have 10 documents and when i query for the states using the query `http://ip:port/solr/select?q=state:Arunachal Pradesh` it returns 10 values with the same state name, But i need the distinct values of state name only, Please help me on this