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 all_project_information table in this repository, by referencing it like:
"mo-gov/all-project-information-sfdx-xhq5:latest"."all_project_information"or in a full query, like:
SELECT
":id", -- Socrata column ID
"location",
"average_award_per_nox_ton", -- Equal to the funding awarded divided by the estimated lifetime NOx reduction (tons) for that specific project.
":@computed_region_ny2h_ckbz", -- This column was automatically created in order to record in what polygon from the dataset 'School Districts' (ny2h-ckbz) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_c8ar_jsdj", -- This column was automatically created in order to record in what polygon from the dataset 'Missouri Counties' (c8ar-jsdj) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_ikxf_gfzr", -- This column was automatically created in order to record in what polygon from the dataset 'Counties' (ikxf-gfzr) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"state",
"zip", -- This is the zip code of the entity
"applicant", -- The entity that applied for funding.
"project_number", -- The number assigned to a vehicle for tracking purposes.
"county", -- County in which entity is located.
"city", -- City in which entity is located.
"mitigation_sub_category", -- MoVW Team funding group. Designates the category of vehicle in terms of the Beneficiary Mitigation Plan.
"eligible_mitigation_action", -- Designated by the Volkswagen Trust.
"old_vehicle_type", -- Body type of vehicle to be disabled.
"new_fuel_type", -- Type of fuel used by the newly purchased vehicle.
"est_lifetime_nox_reduction", -- Calculated NOx reduction using Diesel Emissions Quantifier. Based on information provided by entity during application process.
"funding_requested", -- The amount of funds that the entity has requested.
"funding_awarded", -- The amount of funds awarded by MoVW Team to the entity.
"vehicle_cost", -- The price that the entity paid for the new vehicle.
"address" -- The mailing address for the entitiy
FROM
"mo-gov/all-project-information-sfdx-xhq5:latest"."all_project_information"
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 mo-gov/all-project-information-sfdx-xhq5 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 mo-gov/all-project-information-sfdx-xhq5: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 mo-gov/all-project-information-sfdx-xhq5Checkout 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 mo-gov/all-project-information-sfdx-xhq5:latestThis will download all the objects for the latest tag of mo-gov/all-project-information-sfdx-xhq5 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 mo-gov/all-project-information-sfdx-xhq5: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 mo-gov/all-project-information-sfdx-xhq5: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, mo-gov/all-project-information-sfdx-xhq5 is just another Postgres schema.