15 KiB
Geocoding Functions
The geocoder functions allow you to match your data with geometries on your map. This geocoding service can be used programatically to geocode datasets via the CARTO SQL API. It is fed from Open Data and it serves geometries for countries, provinces, states, cities, postal codes, IP addresses and street addresses. CARTO provides functions for several different categories of geocoding through the Data Services API.
Warning: This service is subject to quota limitations and extra fees may apply. View the Quota Information section for details and recommendations about to quota consumption.
The following example displays how to geocode a single country:
https://{username}.carto.com/api/v2/sql?q=SELECT cdb_geocode_admin0_polygon('USA')&api_key={api_key}
In order to geocode an existent CARTO dataset, an SQL UPDATE statement must be used to populate the geometry column in the dataset with the results of the Data Services API. For example, if the column where you are storing the country names for each one of our rows is called country_column, run the following statement in order to geocode the dataset:
https://{username}.carto.com/api/v2/sql?q=UPDATE {tablename} SET the_geom = cdb_geocode_admin0_polygon('USA')&api_key={api_key}
Notice that you can make use of Postgres or PostGIS functions in your Data Services API requests, as the result is a geometry that can be handled by the system. For example, suppose you need to retrieve the centroid of a specific country, you can wrap the resulting geometry from the geocoder functions inside the PostGIS ST_Centroid function:
https://{username}.carto.com/api/v2/sql?q=UPDATE {tablename} SET the_geom = ST_Centroid(cdb_geocode_admin0_polygon('USA'))&api_key={api_key}
The following geocoding functions are available, grouped by categories.
Country Geocoder
This function geocodes your data into country border geometries. It recognizes the names of the different countries either by different synonyms (such as their English name or their endonym), or by ISO (ISO2 or ISO3) codes.
cdb_geocode_admin0_polygon(country_name text)
Geocodes the text name of a country into a country_name geometry, displayed as polygon data.
Arguments
| Name | Type | Description |
|---|---|---|
country_name |
text |
Name of the country |
Returns
Geometry (polygon, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_admin0_polygon({country_column})
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_admin0_polygon('France')
Level-1 Administrative Regions Geocoder
This function geocodes your data into polygon geometries for Level 1, or NUTS-1, administrative divisions (or units) of countries. For example, a "state" in the United States, "départements" in France, or an autonomous community in Spain.
cdb_geocode_admin1_polygon(admin1_name text)
Geocodes the name of the province/state into a Level-1 administrative region, displayed as a polygon geometry.
Arguments
| Name | Type | Description |
|---|---|---|
admin1_name |
text |
Name of the province/state |
Returns
Geometry (polygon, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_admin1_polygon({province_column})
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_admin1_polygon('Alicante')
cdb_geocode_admin1_polygon(admin1_name text, country_name text)
Geocodes the name of the province/state for a specified country into a Level-1 administrative region, displayed as a polygon geometry.
Arguments
| Name | Type | Description |
|---|---|---|
admin1_name |
text |
Name of the province/state |
country_name |
text |
Name of the country in which the province/state is located |
Returns
Geometry (polygon, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_admin1_polygon({province_column}, {country_column})
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_admin1_polygon('Alicante', 'Spain')
City Geocoder
This function geocodes your data into point geometries for names of cities. It is recommended to use geocoding functions that require more defined parameters — this returns more accurate results when several cities have the same name. If there are duplicate results for a city name, the city name with the highest population will be returned.
cdb_geocode_namedplace_point(city_name text)
Geocodes the text name of a city into a named place geometry, displayed as point data.
Arguments
| Name | Type | Description |
|---|---|---|
city_name |
text |
Name of the city |
Returns
Geometry (point, EPSG 4326) or null
Example
Select
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_namedplace_point({city_column})
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_namedplace_point('Barcelona')
cdb_geocode_namedplace_point(city_name text, country_name text)
Geocodes the text name of a city for a specified country into a named place point geometry.
Arguments
| Name | Type | Description |
|---|---|---|
city_name |
text |
Name of the city |
country_name |
text |
Name of the country in which the city is located |
Returns
Geometry (point, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_namedplace_point({city_column}, 'Spain')
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_namedplace_point('Barcelona', 'Spain')
cdb_geocode_namedplace_point(city_name text, admin1_name text, country_name text)
Geocodes your data into a named place point geometry, containing the text name of a city, for a specified province/state and country. This is recommended for the most accurate geocoding of city data.
Arguments
| Name | Type | Description |
|---|---|---|
city_name |
text |
Name of the city |
admin1_name |
text |
Name of the province/state in which the city is located |
country_name |
text |
Name of the country in which the city is located |
Returns
Geometry (point, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_namedplace_point({city_column}, {province_column}, 'USA')
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_namedplace_point('New York', 'New York', 'USA')
Postal Code Geocoder
These functions geocode your data into point, or polygon, geometries for postal codes. The postal code geocoder covers the United States, France, Australia and Canada; a request for a different country will return an empty response.
Note: For the USA, US Census Zip Code Tabulation Areas (ZCTA) are used to reference geocodes for USPS postal codes service areas. This is not a CARTO restriction, this is a US Government licensing protection of their zip code data source; which is not publicly available. Additionally, zip codes are considered service areas and are not actually geometric areas. As a solution, the US Census provides ZCTA data, which tabulates GIS postal codes for USPS locations by aggregating census blocks. For details about how ZCTAs are created, see ZIP Code™ Tabulation Areas (ZCTAs™). If you are geocoding data and your zip codes fail, ensure you are using ZCTAs for the postal code.
cdb_geocode_postalcode_polygon(postal_code text, country_name text)
Geocodes the postal code for a specified country into a polygon geometry.
Arguments
| Name | Type | Description |
|---|---|---|
postal_code |
text |
Postal code |
country_name |
text |
Name of the country in which the postal code is located |
Returns
Geometry (polygon, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_postalcode_polygon({postal_code_column}, 'USA')
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_postalcode_polygon('11211', 'USA')
cdb_geocode_postalcode_point(code text, country_name text)
Geocodes the postal code for a specified country into a point geometry.
Arguments
| Name | Type | Description |
|---|---|---|
postal_code |
text |
Postal code |
country_name |
text |
Name of the country in which the postal code is located |
Returns
Geometry (point, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_postalcode_point({postal_code_column}, 'USA')
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_postalcode_point('11211', 'USA')
IP Addresses Geocoder
This function geocodes your data into point geometries for IP addresses. This is useful if you are analyzing location based data, based on a set of user's IP addresses.
cdb_geocode_ipaddress_point(ip_address text)
Geocodes a postal code from a specified country into an IP address, displayed as a point geometry.
Arguments
| Name | Type | Description |
|---|---|---|
ip_address |
text |
IPv4 or IPv6 address |
Returns
Geometry (point, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_ipaddress_point('102.23.34.1')
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_ipaddress_point('102.23.34.1')
Street-Level Geocoder
These functions geocode your data into a point geometry for a street address. CARTO platform uses TomTom geocoding services by default as the service provider for street-level geocoding. Contact us if you have any specific questions or requirements about the location data service provider being used with your account.
This service is subject to quota limitations, and extra fees may apply. View the Quota information for details and recommendations about quota consumption.
cdb_geocode_street_point(search_text text, [city text], [state text], [country text])
Geocodes a complete address into a single street geometry, displayed as point data.
Arguments
| Name | Type | Description | |
|---|---|---|---|
searchtext |
text |
searchtext contains free-form text containing address elements. You can specify the searchtext parameter by itself, or with other parameters, to narrow your search. For example, you can specify the state or country parameters, along with a free-form address in the searchtext field. | |
city |
text |
(Optional) Name of the city. | |
state |
text |
(Optional) Name of the state. | |
country |
text |
(Optional) Name of the country. |
Returns
Geometry (point, EPSG 4326) or null
Example
Update the geometry of a table to geocode it
UPDATE {tablename} SET the_geom = cdb_geocode_street_point({street_name_column})
Insert a geocoded row into a table
INSERT INTO {tablename} (the_geom) SELECT cdb_geocode_street_point('651 Lombard Street', 'San Francisco', 'California', 'United States')
cdb_bulk_geocode_street_point (query text, street_column text, [city_column text], [state_column text], [country_column text], [batch_size integer])
Geocodes complete street addresses into point data. Similar to cdb_geocode_street_point, but using batch services and therefore allowing for several addresses to be geocoded in a single API call.
Arguments
| Name | Type | Description | |
|---|---|---|---|
query |
text |
SQL query that returns the addresses to be geocoded. It must include a cartodb_id column and another column to get the free-form addresses from. Optionally, it may include other columns to fine-tune the geocoding, such as a city column, a state column and a country column. |
|
street_column |
text |
Name of the free-form address column, must be present in the SQL query. | |
city_column |
text |
(Optional) Name of the city column, if present in the SQL query. | |
state_column |
text |
(Optional) Name of the state column, if present in the SQL query. | |
country_column |
text |
(Optional) Name of the country column, if present in the SQL query. | |
batch_size |
integer |
(Optional) Geocoding queries are sent in batches. Batch size can be configured, from 1 geocoding query per batch to a maximum value, limited by user quota or other limits. If not specified, it defaults to the maximum size available to the user, which is typically the best option, performance-wise. |
Returns
Geocoding results are returned in an array. Each array element contains:
| Name | Type | Description | |
|---|---|---|---|
cartodb_id |
integer |
cartodb_id from the original query. |
|
the_geom |
Geometry (point, EPSG 4326) |
Point that corresponds to the most accurate match found for this particular address, or null if no match was found. |
|
metadata |
JSON |
Information about the geocoding result, empty if no match was found. |
The metadata JSON type includes the following attributes when geocoding was successful:
| Name | Type | Description | |
|---|---|---|---|
precision |
text |
One of precise or interpolated. |
|
relevance |
number |
Relevance factor, from 0 to 1, higher being more relevant. | |
match_type |
text |
Array with one of point_of_interest, country, state, county, locality, district, street, intersection, street_number, postal_code. Empty array if match type is unknown. |
Example
Update the geometries of an entire table by geocoding all the rows based on a street address
WITH geocoding_results AS (SELECT cartodb_id, the_geom FROM cdb_bulk_geocode_street_point('SELECT cartodb_id, {address_column} from {tablename}', '{address_column}')) UPDATE {tablename} tn SET the_geom = geocoding_results.the_geom FROM geocoding_results WHERE tn.cartodb_id = geocoding_results.cartodb_id