Query the Data Delivery Network
Query the DDNThe 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 eminent_domain_data table in this repository, by referencing it like:
"texas-gov/eminent-domain-data-cvjb-eurw:latest"."eminent_domain_data"or in a full query, like:
SELECT
":id", -- Socrata column ID
"third_party_zip_plus_4", -- Third party's mailing address plus four code
"third_party_zip", -- Third party's mailing address zip code
"third_party_address_line2", -- Third party's mailing address line 2
"physical_county_name", -- Entity's physical address county
"physical_address_zip_plus_4", -- Entity's physical address plus four code
"physical_address_zip", -- Entity's physical address zip code
"physical_state", -- Entity's physical address state
"physical_address_line2", -- Entity's physical address line 2
"mailing_address_line2", -- Entity's mailing address line 2
"mailing_address_line1", -- Entity's mailing address line 1
"third_party_other_relationship", -- Third party relationship description if relationship chosen was other
"third_party_email_id", -- Third party's email address
"parent_company_name", -- Name of entity's parent company
"eminent_domain_begin_year", -- First year the entity received eminent domain authority
"contact_email_address", -- Entity contact's email address
"contact_last_name", -- Entity contact's last name
"website_url", -- Entity's website
"entity_phone_number", -- Main entity telephone number
"tax_payer_id", -- Comptroller's identification number for each entity
"eminent_domain_name", -- Name of the entity claiming eminent domain authority
"third_party_state", -- Third party's mailing address state
"physical_city_name", -- Entity's physical address city
"mailing_county_name", -- Entity's mailing address county
"mailing_address_zip_plus_4", -- Entity's mailing address plus four code
"third_party_url", -- Third party's web address
"other_entity_type", -- Entity type description if entity type chosen was other
"third_party_county_name", -- Third party's mailing address county
"physical_address_line1", -- Entity's physical address line 1
"mailing_state", -- Entity's mailing address state
"eminent_domain_begin_month", -- First month entity received eminent domain authority
"last_updated", -- Timestamp the dataset was updated.
"third_party_address_line1", -- Third party's mailing address line 1
"condemnation_petition", -- Specifies whether the entity filed a condemnation petition in the calendar year preceding the reporting period
"contact_phone_number", -- Entity contact's telephone number
"eminent_domain_public_id", -- Unique ID number for each entity claiming eminent domain authority
"entity_category_type_code", -- Each entity is a specific type that falls in the Governmental or Non-Governmental category
"mailing_city_name", -- Entity's mailing address city
"third_party_phone_number", -- Third party's phone number
"entry_date", -- Most recent date the report was submitted or updated
"contact_title", -- Entity contact's title
"mailing_address_zip", -- Entity's mailing address zip code
"third_party_name", -- Name of the third party that filed the report on behalf of the entity
"report_year", -- Reporting year for the entity's report
"entity_type", -- Entity type, e.g. city, ISD, pipeline facility, etc.
"third_party_city_name", -- Third party's mailing address city
"contact_first_name", -- Entity contact's first name
"id", -- Unique ID number for each report
"third_party_relationship" -- Third party's relationship to the enitty
FROM
"texas-gov/eminent-domain-data-cvjb-eurw:latest"."eminent_domain_data"
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 texas-gov/eminent-domain-data-cvjb-eurw with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.texas.gov. When you querytexas-gov/eminent-domain-data-cvjb-eurw: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
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.texas.gov, 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 \
"texas-gov/eminent-domain-data-cvjb-eurw" \
--handler-options '{
"domain": "data.texas.gov",
"tables": {
"eminent_domain_data": "cvjb-eurw"
}
}'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, texas-gov/eminent-domain-data-cvjb-eurw is just another Postgres schema.