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 degrees_awarded_to_postsecondary_graduates_in table in this repository, by referencing it like:
"colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k:latest"."degrees_awarded_to_postsecondary_graduates_in"or in a full query, like:
SELECT
":id", -- Socrata column ID
"recordcount", -- Record Count. Changes from source: Replaced all * values to null values so that the field type can be treated as an integer field for numerical queries.
"cip", -- Classification of Instructional Programs 2010 code Derived by converting CDHE Colleges & Universities database number into the decimal format found on nces.ed.gov
"residencyid", -- Machine readable coded column denoting if student is in-state or out-of-state. Derived from splitting the number from residency value. 'in-state' : 1, 'out-of-state' :2, 'unclassified/unspecified' :3
"gender", -- Gender of student. Values are: Male, Female, Unknown.
"institutionlevel", -- Human readable column. Changes from source: colum created and populated from the original database field InstitutionType by mapping the number value to 2=College 4=University.
"institutionname", -- The name of the institution. Changes from source: 'Western State University' replaced 'Western State Colorado University' for older years records to maintain consistancy for queries on this university.
"year", -- Year of record. Changes from source: derived by removing the FA- from Data Type field.
"programname", -- Description of the Classification of Instructional Programs code. Original values overwritten in transform with the 2010 CIP datafilehttp://nces.ed.gov
"studentlevel", -- Student level as either Undergraduate or Graduate.
"institutionlevelid", -- Machine readable coded number 2=College or 4=University. Change from source: derived from the original database field InstitutionType.
"agedesc", -- The age range of sample.
"cobased", -- Describes whether the institution is a based in Colorado or is headquartered in a different state. Derived from the CDHE Colleges & Universities database.
"degreelevel", -- Degree level of the student. Values are: Associate, Bachelor, Certificate, Doctoral, Masters, OtherGraduate, Professional, Specialist.
"division", -- Describes the agency aggregating the data. Derived from the CDHE Colleges & Universities database.
"institutiontype", -- Indicates whether the university is public or private. Derived from the CDHE Colleges & Universities database.
"agemin", -- Minimum age from the age description. Changes from source: derived by splitting the ageDesc field and taking the lower end of the value as the min value. 'Under' is set to null values as an unbounded range, treated as an empty value.
"taxtype", -- Describes whether the institution is a non-profit or has another tax designation. Derived from the CDHE Colleges & Universities database.
"cip2", -- Classification of Instructional Programs two digit category code. Derived by splitting up CDHE Colleges & Universities database code into the cip standard format.
"agemax", -- Maximum age from the age description. Changes from source: derived by splitting the ageDesc field and taking the higher end of the value as the max value. 'Over' is set to null values as an unbounded range, and treated as an empty value.
"residency", -- Human readable column derived from original residency retaining the text value. Values are: In-State, Out-Of-State, Unclassified. Changes from source: Values of Unclassified, Unknown have been changed to 'Unclassified'
"ethnicity" -- Ethnicity of student. Values are: Asian or Pacific Islander; Black, non-Hispanic; Hispanic; Native American or Alaskan Native; Non-Resident Alien; Unknown Ethnicity; White, non-Hispanic.
FROM
"colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k:latest"."degrees_awarded_to_postsecondary_graduates_in"
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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k 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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k: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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6kCheckout 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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k:latestThis will download all the objects for the latest tag of colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k 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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k: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 colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k: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, colorado-gov/degrees-awarded-to-postsecondary-graduates-in-hxf8-ab6k is just another Postgres schema.