Merge pull request #56 from CartoDB/iri/geonames

solves #50

geocoder/postal-codes/README.md

@@ -17,9 +17,43 @@ USA polygons - http://www2.census.gov/geo/tiger/TIGER2013/ZCTA5/tl_2013_us_zcta5
 
 French polygons - http://www.data.gouv.fr/dataset/fond-de-carte-des-codes-postaux
 
+All countries points [GeoNames](www.geonames.org) - http://download.geonames.org/export/zip/allCountries.zip
+
 
 ### Preparation details
 
 # Postal code geocoder (points)
 
-todo
+1. Download the allCountries.zip file from [GeoNames](www.geonames.org). Import and rename the table as tmp_zipcode_points. You can follow the manual process explained below instead.
+
+This dataset includes data for the following countries:
+
+````
+CH, ES, GU, ZA, MX, SJ, NL, RU, AX, TH, AR, MY, RE, LK, GB, IS, GL, JE, DK, IN,
+SI, GP, MQ, BR, SM, BG, NZ, MP, CZ, DO, MD, PK, TR, VI, BD, GG, LT, PM, MC, US,
+IT, LU, SK, LI, PR, IM, NO, PT, PL, FI, JP, CA, DE, HU, PH, SE, VA, YT, MK, FR,
+MH, RO, FO, GF, AD, HR, DZ, GT, AU, AS, BE, AT
+````
+
+The columns that are loaded are the following ones:
+field_1: corresponding to ISO2
+field_10: corresponds to latitude
+field_11: corresponds to longitude
+field_2: corresponds to ZIP code
+
+2. Georeference the table using field11 as longitude and field10 as latitude in order to construct the_geom.
+
+3. Add column iso3 (text) and run sql/build_zipcode_points_table.sql.
+
+
+**Alternative manual process**
+
+Open the allCountries.txt file with Excel an add a new row on top. Delete columns C-I and L.
+
+In the first row, add the following columns: iso2, zipcode, lat, long.
+
+Import the file ignoring step 2.
+
+_The big size of the dataset may cause interruptions in the processing of the coordinates after uploading the file, manipulating the file before importing is a faster workaround._
+
+

geocoder/postal-codes/sql/build_zipcode_points_table.sql

@@ -0,0 +1,26 @@
+
+---- Postal Code Points table ---
+
+-- Clear table
+
+DELETE FROM zipcode_points;
+
+-- Insert points
+
+DELETE FROM zipcode_points;
+
+INSERT INTO zip_code_points (the_geom, zipcode, iso3) 
+SELECT the_geom, zipcode,
+		(
+		SELECT country_decoder.iso3 FROM country_decoder 
+		WHERE tmp_zipcode_points.iso2 = country_decoder.iso2
+		)
+FROM tmp_zipcode_points
+);
+
+
+-- Drops temporary table
+
+DROP TABLE tmp_zipcode_points;
+
+