cityofchicago/business-licenses-r5kz-chrr
Icon for Socrata external plugin

Query the Data Delivery Network

Query the DDN

The easiest way to query any data on Splitgraph is via the "Data Delivery Network" (DDN). The DDN is a single endpoint that speaks the PostgreSQL wire protocol. Any Splitgraph user can connect to it at data.splitgraph.com:5432 and query any version of over 40,000 datasets that are hosted or proxied by Splitgraph.

For example, you can query the business_licenses table in this repository, by referencing it like:

"cityofchicago/business-licenses-r5kz-chrr:latest"."business_licenses"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "license_status_change_date",
    ":@computed_region_6mkv_f3dw",
    ":@computed_region_awaf_s7ux",
    ":@computed_region_vrxf_vc4k",
    "application_type",
    "ssa", -- Special Service Areas  are local tax districts that fund expanded services and programs, to foster commercial and economic development, through a localized property tax. In other cities these areas are sometimes called Business Improvement Districts (BIDs). This portal contains a map of all Chicago SSAs
    "conditional_approval", -- This pertains to applications that contain liquor licenses. Customers may request a conditional approval prior to building out the space.
    "license_status",
    "location_address",
    "location_city",
    "location_state",
    "location_zip",
    "state",
    "license_id", -- An internal database ID for each record.  Each license can have multiple records as it goes through renewals and other transactions.  See the LICENSE NUMBER field for the number generally known to the public and used in most other data sources that refer to the license.
    "license_description",
    "application_created_date", -- The date the business license application was created.  RENEW type records do not have an application.
    "location",
    "date_issued",
    "license_start_date",
    "payment_date",
    "application_requirements_complete", -- For all application types except RENEW, this is the date all required application documents were received.  For RENEW type records, this is the date the record was created.
    "ward_precinct", -- The ward and precinct where the business is located. This column can be used to filter by precinct more easily across multiple wards. 
    "ward", -- The ward where the business is located.
    "site_number", -- An internal database ID indicating the location of this licensed business to account for business owners with more than one location.
    "id", -- A calculated ID for each record.
    "business_activity",
    "zip_code",
    "city",
    "precinct", -- The precinct within the ward where the business is located. Note the the same precinct numbers exist in multiple wards.
    "license_code", -- A code for the type of license. Each code value corresponds to a specific LICENSE DESCRIPTION value.
    "license_number", -- The license number known to the public and generally used in other data sources that refer to the license. This is the field most users will want for most purposes. Each license has a single license number that stays consistent throughout the lifetime of the license. By contrast, the LICENSE ID field is an internal database ID and not generally useful to external users.
    "doing_business_as_name",
    "latitude",
    "address",
    "business_activity_id", -- A code for the business activity. Each ID value corresponds to a specific BUSINESS ACTIVITY value.
    "longitude",
    "expiration_date",
    "legal_name",
    "license_approved_for_issuance", -- This is the date the license was ready for issuance. Licenses may not be issued if the customer owes debt to the City. 
    "account_number", -- The account number of the business owner, which will stay consistent across that owner's licenses and can be used to find the owner in the Business Owners dataset.
    "police_district",
    ":@computed_region_43wa_7qmu",
    ":@computed_region_bdys_3d7i"
FROM
    "cityofchicago/business-licenses-r5kz-chrr:latest"."business_licenses"
LIMIT 100;

Connecting to the DDN is easy. All you need is an existing SQL client that can connect to Postgres. As long as you have a SQL client ready, you'll be able to query cityofchicago/business-licenses-r5kz-chrr with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cityofchicago.org. When you querycityofchicago/business-licenses-r5kz-chrr:latest on the DDN, we "mount" the repository using the socrata mount handler. The mount handler proxies your SQL query to the upstream data source, translating it from SQL to the relevant language (in this case SoQL).

We also cache query responses on the DDN, but we run the DDN on multiple nodes so a CACHE_HIT is only guaranteed for subsequent queries that land on the same node.

Query Your Local Engine

Install Splitgraph Locally
bash -c "$(curl -sL https://github.com/splitgraph/splitgraph/releases/latest/download/install.sh)"
 

Read the installation docs.

Splitgraph Cloud is built around Splitgraph Core (GitHub), which includes a local Splitgraph Engine packaged as a Docker image. Splitgraph Cloud is basically a scaled-up version of that local Engine. When you query the Data Delivery Network or the REST API, we mount the relevant datasets in an Engine on our servers and execute your query on it.

It's possible to run this engine locally. You'll need a Mac, Windows or Linux system to install sgr, and a Docker installation to run the engine. You don't need to know how to actually use Docker; sgrcan manage the image, container and volume for you.

There are a few ways to ingest data into the local engine.

For external repositories (like this repository), the Splitgraph Engine can "mount" upstream data sources by using sgr mount. This feature is built around Postgres Foreign Data Wrappers (FDW). You can write custom "mount handlers" for any upstream data source. For an example, we blogged about making a custom mount handler for HackerNews stories.

For hosted datasets, where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.

Mounting Data

This repository is an external repository. It's not hosted by Splitgraph. It is hosted by data.cityofchicago.org, and Splitgraph indexes it. This means it is not an actual Splitgraph image, so you cannot use sgr clone to get the data. Instead, you can use the socrata adapter with the sgr mount command. Then, if you want, you can import the data and turn it into a Splitgraph image that others can clone.

First, install Splitgraph if you haven't already.

Mount the table with sgr mount

sgr mount socrata \
  "cityofchicago/business-licenses-r5kz-chrr" \
  --handler-options '{
    "domain": "data.cityofchicago.org",
    "tables": {
        "business_licenses": "r5kz-chrr"
    }
}'

That's it! Now you can query the data in the mounted table like any other Postgres table.

Query the data with your existing tools

Once you've loaded the data into your local Splitgraph engine, you can query it with any of your existing tools. As far as they're concerned, cityofchicago/business-licenses-r5kz-chrr is just another Postgres schema.