state abbreviations are not globally unique

[jsm222]

Expected Behavior

All countries states are not mixed up

Actual Behavior

Some countries states are mixed up (For instance 82 for state_abbr)

Steps to reproduce the problem

Run without specifying a country

cut -d'       ' -f4,5 allCountries.txt | grep 82 | cut -d'    ' -f1 | sort | uniq

insert

-d'       '

with CTRL+V TAB

These adm1 share 82 as abbr: (As example)
Çankiri
Khulna Division
Královéhradecký kraj
Phang Nga
Pomerania
Region Midtjylland

---

• Current Version: 1.0.2
• Operating System: FreeBSD

A possible workaround
Instead of

free_zipcode_data/lib/free_zipcode_data/db_table.rb

Line 48 in 292a336

WHERE abbr = '#{state_abbr}' OR name = '#{escape_single_quotes(state_name)}'"

    def get_state_id(state_abbr, state_name)
      sql = "SELECT id FROM states
        WHERE abbr = '#{state_abbr}' and  name = '#{escape_single_quotes(state_name)}'"
      res = select_first(sql)
      if(res == nil) 
         sql = "SELECT id FROM states WHERE name = '#{escape_single_quotes(state_name)}'"
         res=select_first(sql)
      end
      return res
    end

The fallback to test only for name is required because of mixed up state_abbr in Denmark's data (One State (Region) has two abbr's for the same state name i.e the state has one name but falsely in the dataset two abbr's, (More of data a date quality issue) and perhaps other countries as well.
EDIT: Perhaps using country_id in the state_id lookup would be better...
BTW South Africa does not have a adm1 (state) so I used country for state like this

 def write(row)
      if(row[:short_state] == nil || row[:short_state] == '')
        row[:short_state] = row[:country]
        row[:state] = country_lookup_table[row[:country]][:name]
      end
      return nil unless row[:short_state]
      row[:state] = 'Marshall Islands' if row[:short_state] == 'MH' && row[:state].nil?
      country_id = get_country_id(row[:country])
      sql = <<-SQL
        INSERT INTO states (abbr, name, country_id)
        VALUES ('#{row[:short_state]}',
          '#{escape_single_quotes(row[:state])}',
          #{country_id}
        )
      SQL
      begin
        database.execute(sql)
      rescue SQLite3::ConstraintException
        # Swallow duplicates
      end

[midwire]

Thanks for this. A pull request would be most appreciated.