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 county_actual_revenues_by_type_by_fiscal_year table in this repository, by referencing it like:
"mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd:latest"."county_actual_revenues_by_type_by_fiscal_year"or in a full query, like:
SELECT
":id", -- Socrata column ID
"general_long_term_debt", -- Proceeds from issuance of long-term debt obligations during the fiscal year.
"penalties_interest_costs", -- Revenue received from payment of penalties and interest.
"net_current_property_taxes", -- Amount of Property Taxes Levied on Property, less Uncollected Delinquent Taxes and Credits to Taxpayers.
"less_credits_to_taxpayers", -- Amount of credit given to property taxpayers on their tax statements. This is treated as a reduction of Taxes Levied on Property revenue.
"less_uncollected_delinquent", -- Property tax dollars that were expected but not received during the fiscal year. This is treated as a reduction of Taxes Levied on Property revenue.
"county_name", -- Name of the county the actual revenues are related with.
"county_number", -- Number used to track county level data.
"geocoded_column", -- Latitude and longitude for the center point of the county.
"total_revenues_other_sources", -- Total of all revenues during the fiscal year.
"proceeds_of_capital_asset", -- Proceeds from the sale of assets during the fiscal year.
"subtotal_revenues", -- Subtotal of all revenues except Operating Transfers In, Long-Term Debt proceeds, and Fixed Asset Sales.
"licenses_permits", -- Revenue received from building structure, equipment and environmental licenses and permits.
"taxes_levied_on_property", -- Amount of property taxes received from taxpayers during the fiscal year.
"use_of_money_property", -- Revenue to be received from interest on held cash balances and rents collected during the fiscal year.
"other_county_taxes_tif_tax", -- All tax revenues received by the County which are not related to tax of owned property.
"fiscal_year", -- Fiscal year which the actual revenues are associated. Fiscal years run from July 1 to June 30.
"operating_transfers_in", -- Amount of transferred dollars between funds during the fiscal year.
"delinquent_property_tax", -- Taxes levied on property in previous years not received until the fiscal year shown.
"miscellaneous", -- Revenues to be received from contributions, deposits and refunds, sale of merchandise and fines.
"charges_for_service", -- Revenue received from fees paid for county provided goods and services.
"intergovernmental", -- Revenues received from Federal, State and other local government sources.
":@computed_region_3r5t_5243",
":@computed_region_wnea_7qqw",
":@computed_region_i9mz_6gmt",
":@computed_region_e7ym_nrbf",
":@computed_region_uhgg_e8y2"
FROM
"mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd:latest"."county_actual_revenues_by_type_by_fiscal_year"
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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd 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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd: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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hdCheckout 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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd:latestThis will download all the objects for the latest tag of mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd 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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd: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 mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd: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, mydata-iowa-gov/county-actual-revenues-by-type-by-fiscal-year-fp2u-f5hd is just another Postgres schema.