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 l7_employment_of_legislators_and_state_officials table in this repository, by referencing it like:
"wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8:latest"."l7_employment_of_legislators_and_state_officials"or in a full query, like:
SELECT
":id", -- Socrata column ID
"user_data", -- JSON representation of the submission as it was filed to the PDC.
"public_employment_description", -- The nature of state office or employment. (What the public employee does for the state).
"lobbyist_employment_compensation", -- The amount and nature of pay or consideration.
"lobbyist_postcode", -- Postcode of the lobbyist filing the submission.
"lobbyist_address", -- Address of the lobbyist filing the submission.
"amended_by", -- This field only applies to submissions which have been superseded by an amendment. The value is the submission ID of the newer version of the report.
"id", -- PDC internal identifier that corresponds to a single submission or correction submission. When combined with the origin value, this number uniquely identifies a single row.
"lobbyist_employment_description", -- The nature of employment by the reporting employer. (What the public employee does for the lobbyist).
"employee_name", -- Name of the public employee that was hired by the lobbyist.
"lobbyist_city", -- City of the lobbyist filing the submission.
"lobbyist_name", -- Name of the lobbyist filing the submission.
"lobbyist_type", -- Indicator that the submission was filed by a lobbyist client or a lobbyist firm.
"client_id", -- This field only applies to submissions that have been filed by a lobbyist client.
"firm_id", -- This field only applies to submissions that have been filed by a lobbyist firm.
"receipt_date", -- Date submission was filed to the PDC.
"amends", -- This field only applies to submissions which amend a prior report. The value is the submission ID of the previous version of the report that is superseded by this record.
"report_number", -- A report has many submissions in a one-to-many relationship. This is to keep track of the report history, the current submission, and the amend chain.
"pdc_report_url", -- A link to a printable version of the original submission as it was filed to the PDC.
"lobbyist_state" -- State of the lobbyist filing the submission.
FROM
"wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8:latest"."l7_employment_of_legislators_and_state_officials"
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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8 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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8: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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8Checkout 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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8:latestThis will download all the objects for the latest tag of wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8 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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8: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 wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8: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, wa-gov/l7-employment-of-legislators-and-state-officials-ef7g-tyg8 is just another Postgres schema.