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 cityparish_expenditures table in this repository, by referencing it like:
"brla-gov/cityparish-expenditures-vwa8-ps2a:latest"."cityparish_expenditures"or in a full query, like:
SELECT
":id", -- Socrata column ID
"vendor_type", -- Indicates the type of business the vendor is in
"program_id", -- The numerical value of the program of the fund used to pay the expenditure.
"source_document_type", -- P = Purchase Order; C = Contract
"payment_type", -- Type of payment used to pay the vendor (Check, Wire or ACI (P-Cards)).
"status", -- Vendor's status A=Active, B=Bidder, I=Inactive, O=One Time Pay, S=Stop, T=Temporary, S=Self Service
"minority", -- Is the vendor a minority business enterprise
"disabled_veteran", -- Disabled veteran business enterprise
"sb_non_minority", -- Small business non-minority owned
"payment_status", -- Status of payment (Cleared and Not Cleared).
"sb_veteran", -- Small business veteran owned
"geographic_area", -- Geographic area of vendor (INP=In EBR Parish, INS=In State, USA=In Country, INTL=International
"department_id", -- The numerical value of the department under which the expenditure is authorized and recorded.
"ethnicity",
"subprogram", -- The subprogram of the fund used to pay the expenditure.
"vendor_name_2", -- Vendor doing business as (DBA) name
"sb_disadvantaged", -- Small business disadvantaged business enterprise
"invoice_status", -- Status of the invoice P = Paid or V = Voided
"commodity_code", -- Code classifying the type of good/service being purchased.
"gender",
"independent_contractor",
"sb_minority", -- Small business minority owned
"sb_disabled_vet", -- Small business disabled veteran
"function_id", -- The numerical value of the function/purpose of the fund used to pay the expenditure.
"journal_entry_period", -- The month in which the expenditure was recorded.
"expense_category", -- Description of the expenditure type.
"fund_id", -- The numerical value of the fund utilized to pay the expenditure.
"line_number", -- Line number of the specific expenditure for the corresponding invoice.
"purchasing_department", -- The department making the purchase
"class", -- The vendor's classification (LLC, Corporation, Sole Proprietor, etc)
"sb_minority_woman", -- Small business minority woman owned
"disadvantaged", -- Disadvantaged business enterprise
"year", -- The year in which the expenditure was recorded.
"vendor_state",
"program", -- The program of the fund used to pay the expenditure.
"subprogram_id", -- The numerical value of the subprogram of the fund used to pay the expenditure.
"invoice_line_item_amount", -- The total value requested for payment through the invoice.
"invoice_number", -- The id associated with the vendor's invoice that itemizes justification for payment.
"source_document_number", -- The purchase order or contract number of the document used to procure the goods or services.
"check_number", -- The numerical value of the check issued to pay the vendor for the expenditure.
"sb_woman", -- Small business woman owned
"division", -- The name of the division (within the department) under which the expenditure is authorized and recorded.
"vendor_city",
"fund", -- The budgetary name of the fund utilized to pay the expenditure.
"department", -- The name of the department under which the expenditure is authorized and recorded.
"function", -- The function/purpose of the fund used to pay the expenditure.
"division_id", -- The numerical value of the division (within the department) under which the expenditure is authorized and recorded.
"check_date", -- The date the check was issued to the vendor.
"invoice_date", -- The date the invoice was issued to the City-Parish for processing and payment.
"invoice_line_item_description", -- A description of the specific expenditure for the corresponding invoice.
"source_document_description", -- A description of the purchase order or contract.
"expense_category_id", -- The numerical value of the expenditure type used to track and classify types of expenditures within the City-Parish financial system.
"purchasing_department_id", -- ID indicating the department making the purchase
"commodity_description", -- Description classifying the type of good/service being purchased.
"vendor_name_1", -- Vendor's primary business name
"vendor_zip"
FROM
"brla-gov/cityparish-expenditures-vwa8-ps2a:latest"."cityparish_expenditures"
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/cityparish-expenditures-vwa8-ps2a with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.brla.gov. When you querybrla-gov/cityparish-expenditures-vwa8-ps2a:latest on the DDN, we "mount" the repository using the socrata mount handler. The mount handler proxies your SQL query to the upstream data source, translating it from SQL to the relevant language (in this case SoQL).
We also cache query responses on the DDN, but we run the DDN on multiple nodes so a CACHE_HIT is only guaranteed for subsequent queries that land on the same node.
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 (like this repository), 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, where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Mounting Data
This repository is an external repository. It's not hosted by Splitgraph. It is hosted by data.brla.gov, and Splitgraph indexes it. This means it is not an actual Splitgraph image, so you cannot use sgr clone to get the data. Instead, you can use the socrata adapter with the sgr mount command. Then, if you want, you can import the data and turn it into a Splitgraph image that others can clone.
First, install Splitgraph if you haven't already.
Mount the table with sgr mount
sgr mount socrata \
"brla-gov/cityparish-expenditures-vwa8-ps2a" \
--handler-options '{
"domain": "data.brla.gov",
"tables": {
"cityparish_expenditures": "vwa8-ps2a"
}
}'That's it! Now you can query the data in the mounted table like any other Postgres table.
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/cityparish-expenditures-vwa8-ps2a is just another Postgres schema.