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 summer_meal_programs_summer_food_service_program table in this repository, by referencing it like:
"texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t:latest"."summer_meal_programs_summer_food_service_program"or in a full query, like:
SELECT
":id", -- Socrata column ID
"breakfastdays", -- Number of days breakfast meals were served at site for claim month
"pmsnackdays", -- Number of days afternoon snacks were served at site for claim month
"pmsnacktotal", -- Total number of afternoon snacks served at site for claim month
"ruralorurbancode", -- Description of geographic location for the participating site. Data displayed as: Rural/Urban
"secondsupper", -- Number of second helping supper meals served at site for claim month
"sitecounty", -- County in which the site is located
"suppertotal", -- Total suppers served by site for claim month
"lunchdays", -- Number of days lunch meals were served at site for claim month
"supperdays", -- Number of days supper meals served at site for claim month
"breakfast", -- Number of breakfast meals served at site for claim month
"covidmealsite", -- COVID-19 Meal Site indicator, Indicates whether site is operating under USDA flexibilities offered in response to the COVID-19 pandemic. Data displayed as: Yes/No.
"amsnackdays", -- Number of days morning snacks were served at site for claim month
"sitename", -- Site name
"ceid", -- Unique number assigned by TDA to Contracting Entity (CE) to identify organization as program sponsor
"secondlunch", -- Number of second helping lunch meals served at site for claim month
"siteid", -- Identification number assigned to site under CE sponsorship
"supper", -- Number of supper meals served for claim month
"esc", -- Educational Service Center (ESC) region
"typeoforg", -- Type of organization the Contracting Entity (CE) operates as within a specific nutrition program. Data for SFSP displayed as: Nonresidential Summer Camp/Private Non Profit/Residential Camp/School Food Authority/Unit of Government.
"secondpmsnack", -- Number of second helping afternoon snacks served at site for claim month
"cecounty", -- County in which the Contracting Entity (CE) is located.
"typeofagency", -- Type of agency the Contracting Entity (CE) operates as. Data displayed as: Educational Institution/For Profit Organization/Government Agency/Indian Tribe/Military Installation/Private Non Profit Organization/Other
"cename", -- Contracting Entity (CE) name
"amsnack", -- Number of morning snacks served for claim month
"tdaregion", -- Texas Department of Agriculture (TDA) service region
"reporttype", -- Type of information being reported in the dataset
"programyear", -- A program period for summer meal programs (SFSP and SSO) is defined as mid-May through the end of August for the same calendar year.
"claimdate", -- Month and year meals were served
"pmsnack", -- Number of afternoon snacks served for claim month
"secondamsnack", -- Number of second helping morning snacks served at site for claim month
"lunch", -- Number of lunch meals served for claim month
"breakfasttotal", -- Total breakfasts served by site for claim month
"lunchtotal", -- Total lunches served by site for claim month
"secondbreakfast", -- Number of second helping breakfast meals served at site for claim month
"amsnacktotal" -- Total number of morning snacks served at site for claim month
FROM
"texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t:latest"."summer_meal_programs_summer_food_service_program"
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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t 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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t: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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8tCheckout 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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t:latestThis will download all the objects for the latest tag of texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t 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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t: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 texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t: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, texas-gov/summer-meal-programs-summer-food-service-program-j4qf-ft8t is just another Postgres schema.