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 transportation_projects_funded_through_the table in this repository, by referencing it like:
"fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf:latest"."transportation_projects_funded_through_the"or in a full query, like:
SELECT
":id", -- Socrata column ID
"initiatve_type",
"project_type", -- Used to categorize project by type.
"tier", -- The project tier (1, 2 or 3) indicating the priority. The completion of Tier 2 and 3 projects are contingent on availability of funds.
"committed_not_spent", -- The amount committed but not yet spent in dollars.
"budget_indicator", -- Text indicating whether the project is currently within budget.
"indicator_color_for_schedule",
"description_assocated_with_schedule_indicator_color", -- Text indicating whether the project is currently on schedule.
"pending_steps_for_project_budget",
"text_to_descript_the_schedule_status_for_the_project",
"district_shape_file",
"estimated_substantial_completion_date", -- The date by which work is estimated to be substantially completed.
"status", -- The current status of the project (active or inactive).
"editor", -- The last person to edit the project information.
"link_to_external_website_if_it_exists_with_city", -- A link to a web page with additional information about the project.
"image_file",
"status_budget_narative",
"creationdate",
"address",
"state",
"lastupdate",
"balance_to_spend",
"project_name_title", -- A short name for the project
"projectyear",
"local_id", -- Unique project identifier created by the municipality
"project_id", -- Unique project identifier created by Fulton County
"id", -- Internally generated unique identifier
"project_description", -- A description of the project including the location and the type of improvements to be made.
"current_stage_of_project", -- The current stage of the project (planning, land, concept, design, bidding, construction or completed).
"city", -- Name of city to which the project belongs
"construction_firm_selected", -- The name of the firm selected to do the construction work.
"design_firm_selected", -- The name of the firm selected to do the design work.
"estimated_design_completion_date", -- The date by which the design work is estimated to be completed.
"estimated_start_date_for_project", -- The date by which the project is estimated to start.
"estimated_construction_completion_date", -- The date by which the construction work is estimated to be completed.
"primary_funding_source", -- The primary source of funding for the projects (TSPLOST).
"budget", -- The project budget in dollars.
"spent" -- The amount spent so far in dollars.
FROM
"fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf:latest"."transportation_projects_funded_through_the"
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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf 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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf: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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwfCheckout 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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf:latestThis will download all the objects for the latest tag of fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf 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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf: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 fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf: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, fultoncountyga-gov/transportation-projects-funded-through-the-5kk5-4dwf is just another Postgres schema.