Custom query to fetch all entries of a table and that only contains first of many duplicates based on a specific column

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I have a Location model and the table looks like

id name vin ip_address created_at updated_at
0 default 0 0.0.0.0/0 2021-11-08 11:54:26.822623 2021-11-08 11:54:26.822623
1 admin 1 10.108.150.143 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
2 V122 122 10.108.150.122 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
3 V123 123 10.108.150.123 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
4 V124 124 10.108.150.124 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
5 V122 122 10.108.150.122 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
6 V125 122 10.108.150.125 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885

My method in the Location model

   def self.find_all_non_duplicate
     return self.find(:all, :conditions => "id <> 1")
   end

I want to fetch all entries of the locations table except the entry with id = 1 and that contains only the first entry of many duplicates based on the column ip_address.

Since ip_address of id = 2 and id = 5 is duplicate. I want to keep the first entry of many duplicates i.e., id = 2.

The expected result is

id name vin ip_address created_at updated_at
0 default 0 0.0.0.0/0 2021-11-08 11:54:26.822623 2021-11-08 11:54:26.822623
2 V122 122 10.108.150.122 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
3 V123 123 10.108.150.123 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
4 V124 124 10.108.150.124 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885
6 V125 122 10.108.150.125 2021-11-08 11:54:26.82885 2021-11-08 11:54:26.82885

The entries with id's 1 and 5 to be ignored



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