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 benefits_and_programs_api_historical table in this repository, by referencing it like:
"cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latest"."benefits_and_programs_api_historical"or in a full query, like:
SELECT
":id", -- Socrata column ID
"office_locations_url", -- Link to location finder on ACCESS NYC - where map of in-person application centers is available.
"language", -- Language of program information.
"how_to_apply_or_enroll_by_phone", -- Instructions for how to apply to the program by phone.
"program_code", -- Code used for screening in ACCESS NYC ONLY.
"unique_id_number", -- Unique identifier.
"program_category", -- Type of program.
"program_name", -- Official name of program (e.g. Supplemental Nutrition Assistance Program).
"population_served", -- Target population for program.
"age_group", -- Target age group for program.
"brief_excerpt", -- One sentence description of program.
"apply_online_call_to_action", -- Call to action phrase for applying online (e.g. "Apply online," "File online").
"get_help_online", -- How to get help online, with link(s) to the administering agency's website.
"get_help_by_calling_other_than_311", -- How to get help by calling the administering agency, and the phone number.
"get_help_by_email", -- How to get help/questions answered by email from the administering agency.
"required_documents_summary", -- A summary of the documents required to apply for this program.
"url_of_pdf_application_forms", -- Link to download the PDF application form.
"program_acronym", -- Acronym for program (e.g. SNAP).
"get_help_summary", -- A summary of the different ways you can get help with this program.
"how_to_apply_or_enroll_by_mail", -- Instructions for how to apply to the program by mail.
"date",
"plain_language_program_name", -- A plain language name for the program that describes what it is or does (e.g. SNAP = Money to buy food).
"apply_in_person_call_to_action", -- Call to action phrase for applying in person (e.g. "Find a location").
"program_description", -- Plain language description of what the program is and how it works.
"heads_up", -- List of key program attributes/common questions (e.g. facts, application formats, citizenship status, deadlines).
"get_help_by_calling_311", -- How to get help by calling 311 and what to ask for, or 911 for emergencies.
"how_to_apply_or_enroll_in_person", -- Instructions for how to apply to the program in person.
"apply_by_mail_call_to_action", -- Call to action phrase for applying by mail (usually "Download the form").
"how_to_apply_summary", -- Summary of the different ways to apply for the program.
"how_to_apply_or_enroll_online", -- Instructions for how to apply to the program online.
"get_help_in_person", -- How to get help in person, with a link to the administering agency's in-person centers (ACCESS NYC locations page), or the address for the center.
"plain_language_eligibility", -- Plain language overview of the eligibility requirements for the program.
"url_of_online_application", -- Link to the online application for the program.
"page_type", -- Type of information.
"government_agency" -- Name of administering government agency(ies).
FROM
"cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latest"."benefits_and_programs_api_historical"
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 cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju with SQL in under 60 seconds.
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, 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 (like this repository), where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Cloning Data
Because cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latest is a Splitgraph Image, you can clone the data from Spltgraph Cloud to your local engine, where you can query it like any other Postgres database, using any of your existing tools.
First, install Splitgraph if you haven't already.
Clone the metadata with sgr clone
This will be quick, and does not download the actual data.
sgr clone cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtjuCheckout the data
Once you've cloned the data, you need to "checkout" the tag that you want. For example, to checkout the latest tag:
sgr checkout cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latestThis will download all the objects for the latest tag of cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju and load them into the Splitgraph Engine. Depending on your connection speed and the size of the data, you will need to wait for the checkout to complete. Once it's complete, you will be able to query the data like you would any other Postgres database.
Alternatively, use "layered checkout" to avoid downloading all the data
The data in cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latest is 0 bytes. If this is too big to download all at once, or perhaps you only need to query a subset of it, you can use a layered checkout.:
sgr checkout --layered cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju:latestThis will not download all the data, but it will create a schema comprised of foreign tables, that you can query as you would any other data. Splitgraph will lazily download the required objects as you query the data. In some cases, this might be faster or more efficient than a regular checkout.
Read the layered querying documentation to learn about when and why you might want to use layered queries.
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, cityofnewyork-us/benefits-and-programs-api-historical-2j8u-wtju is just another Postgres schema.