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 purchase_orders_and_contracts table in this repository, by referencing it like:
"brla-gov/purchase-orders-and-contracts-2ung-w7t4:latest"."purchase_orders_and_contracts"or in a full query, like:
SELECT
":id", -- Socrata column ID
"vendor_status", -- Vendor's status A=Active, B=Bidder, I=Inactive, O=One Time Pay, S=Stop, T=Temporary, S=Self Service
"source_doc_status_description", -- Description of the status of the PO/Contract.
"object_desc", -- The description of the type of expense for this good/service.
"commodity_code", -- Code classifying the type of good/service being purchased.
"item_total_cost", -- Total (extended) cost of the PO/Contract line item being ordered.
"item_unit_cost", -- Unit Cost for this PO/Contract line item.
"vendor_type", -- Indicates the type of business the vendor is in.
"dept_num", -- Number of the department which the PO/Contract is for
"requisition_no", -- Requisition number used for purchase.
"item_number", -- Sequential number of the detail PO/Contract line item.
"vendor_city",
"vendor_name_1", -- Vendor's primary business name
"extended_through_date", -- For contracts only, date contract has been extended
"initial_expiration_date", -- For contracts only, expected date for work to end
"estimated_start_date", -- For contracts only, estimated date for work to begin
"vouched_amount", -- Actual amount invoiced against PO/Contract. This amount may be less than the original PO/Contract amount.
"source_doc_type_description", -- Description of the type of PO/Contract.
"cost_center_name", -- Description of Cost Center of the Department which the PO/Contract is for. This will often show which of the Department's Divisions issued the PO/Contract
"cost_center", -- Cost Center of the Department which the PO/Contract is for. This will often show which of the Department's Divisions issued the PO/Contract
"total_amount", -- Total amount of PO/Contract
"source_doc_status_code", -- Code indicating the status of the PO/Contract.
"input_date", -- Date PO/Contract was entered into the system
"record_type", -- H or D. H indicates record is a header record. D indicates a detail record. A PO/Contract will have 1 header record and at least 1 detail item
"item_quantity_ordered", -- Quantity being ordered for this PO/Contract line item.
"vendor_ethnicity",
"isminority", -- Is the vendor a minority business enterprise
"dvbe", -- Disabled veteran business enterprise
"smb_woman", -- Small business woman owned
"vendor_class", -- The vendor's classification (LLC, Corporation, Sole Proprietor, etc)
"source_doc_type", -- Code representing the type of PO/Contract P = Purchase Order, C = Contract
"vendor_gender",
"sb_non_mn", -- Small business non-minority owned
"vet_sm_bus", -- Small business veteran owned
"dvse", -- Small business disabled veteran
"smb_min", -- Small business minority owned
"annual_contract", -- For PO only, the annual contract this PO was purchased from
"smb_mn_wom", -- Small business minority woman owned
"smb_dbe", -- Small business disadvantaged business enterprise
"dbe", -- Disadvantaged business enterprise
"vendor_independent_contractor", -- Whether or not the vendor is an independent contractor
"dept_name", -- Department name which the PO/Contract is for
"source_doc_type_code", -- Code indicating the type of PO/Contract.
"vendor_name_2", -- Vendor doing business as (DBA) name
"vendor_state",
"total_items", -- Total number of detail items on PO/Contract. Each PO/Contract will have at least 1 detail item.
"vendor_geographic_code", -- Geographic area of vendor (INP=In EBR Parish, INS=In State, USA=In Country, INTL=International
"vendor_zip",
"source_doc_desc", -- Description of the good/service being procured.
"source_document", -- Numeric ID of the PO/Contract
"item_description", -- Description of good or service being ordered on this PO/Contract line item.
"object", -- The code indicating the type of expense for this good/service.
"commodity_desc", -- Description classifying the type of good/service being purchased.
"item_unit_of_mea" -- Code indicating Unit of Measure for this PO/Contract line item.
FROM
"brla-gov/purchase-orders-and-contracts-2ung-w7t4:latest"."purchase_orders_and_contracts"
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 brla-gov/purchase-orders-and-contracts-2ung-w7t4 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 brla-gov/purchase-orders-and-contracts-2ung-w7t4: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 brla-gov/purchase-orders-and-contracts-2ung-w7t4Checkout 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 brla-gov/purchase-orders-and-contracts-2ung-w7t4:latestThis will download all the objects for the latest tag of brla-gov/purchase-orders-and-contracts-2ung-w7t4 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 brla-gov/purchase-orders-and-contracts-2ung-w7t4: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 brla-gov/purchase-orders-and-contracts-2ung-w7t4: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, brla-gov/purchase-orders-and-contracts-2ung-w7t4 is just another Postgres schema.