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 work_orders table in this repository, by referencing it like:
"norfolk-gov/work-orders-qzfe-wj25:latest"."work_orders"or in a full query, like:
SELECT
":id", -- Socrata column ID
"primary_task_code", -- Code assigned to the primary action to be taken in response to the work order.
"start_date", -- Date the work on the work order began.
"created_datetime", -- Date and time the work order was created.
"status_datetime", -- Last date and time that the status of the work order was updated.
"status_description", -- Current status of the work order.
"status_code", -- Code assigned to the current status of the work order.
"primary_task_description", -- A brief description of the primary action to be taken in response to the work order.
"reason", -- Source of the problem to be remedied; used for work orders associated with storms.
"problem_description", -- Description of the problem.
"problem_code", -- Code assigned to the problem type.
"category_description", -- Description of the work order category.
"category_code", -- Code assigned to the work order category.
"work_order_number", -- A unique number assigned by the system to identify the work order.
"neighborhood_service_area", -- Neighborhood Service Area that the work order is located in. If a work order spans multiple service areas, only the one associated with the primary street will be displayed.
"planning_district", -- Planning District that the work order is located in. If a work order spans multiple planning districts, only the one associated with the primary street will be displayed.
"civic_league", -- Civic League that the work order is located in. If a work order spans multiple civic leagues, only the one associated with the primary street will be displayed.
"superward", -- Superward that the work order is located in. If a work order spans both superwards, only the one associated with the primary street will be displayed.
"ward", -- Ward that the work order is located in. If a work order spans multiple wards, only the one associated with the primary street will be displayed.
"maintenance_zone", -- Maintenance zone that the work order is located in. If a work order spans multiple zones, only the one associated with the primary street will be displayed.
"street", -- Name of the street where the work is to be performed. If a work order spans multiple streets, only the primary one will be displayed.
"total_cost", -- Total of Actual Labor Cost, Actual Equipment Cost, Actual Material Cost, and Contractor Cost.
"contractor_cost", -- Cost of contractor labor and materials in completing the work order.
"actual_material_cost", -- Cost of City purchased materials in completing the work order.
"actual_equipment_cost", -- Cost of City equipment in completing the work order.
"actual_labor_cost", -- Cost of City labor in completing the work order.
"inventory_type", -- The type of asset worked on. If a work order spans multiple types of assets, only the primary one will be displayed.
"assigned_crew", -- Name of the work crew that has been assigned to the work order.
"department", -- Name of the department that is responsible for the work order.
"area", -- Name of the department or division that is responsible for the work order.
"priority", -- Priority description of the work order.
"last_modified_datetime", -- Date and time the work order was last modified.
"end_date" -- Date the work on the work order was completed.
FROM
"norfolk-gov/work-orders-qzfe-wj25:latest"."work_orders"
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 norfolk-gov/work-orders-qzfe-wj25 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 norfolk-gov/work-orders-qzfe-wj25: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 norfolk-gov/work-orders-qzfe-wj25Checkout 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 norfolk-gov/work-orders-qzfe-wj25:latestThis will download all the objects for the latest tag of norfolk-gov/work-orders-qzfe-wj25 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 norfolk-gov/work-orders-qzfe-wj25: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 norfolk-gov/work-orders-qzfe-wj25: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, norfolk-gov/work-orders-qzfe-wj25 is just another Postgres schema.