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 commonwealth_revenue_collections table in this repository, by referencing it like:
"cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi:latest"."commonwealth_revenue_collections"or in a full query, like:
SELECT
":id", -- Socrata column ID
"fund_number", -- All revenue and spending activity is allocated to more than 115 statutorily defined funds, such as the General Fund (for general government operations), the Commonwealth Transportation Fund (for transportation-related activity), State Lottery Fund, Federal Grants Fund, and agency fund.
"revenue_category_name", -- Revenues are classified into 15 different broad revenue categories, the most important being tax revenues, federal government grants and reimbursements, higher education revenues, departmental revenues (fees, fines, and other charges) assessments, chargeback revenues (where one state department provides services to another department and charges the second department a fee), and other financing sources (transfers from other government funds).
"apd_nm",
"fiscal_year", -- The period during which a fiscal year's budget may be expended. This period for any fiscal year is from July 1st of the preceding calendar year through June 30th of the current calendar year. It is the period within which all goods and/or services must be received to be payable with those fiscal year funds. For example, fiscal year 2018 began on July 1, 2017 and ended on June 30, 2018.
"fund_name", -- All revenue and spending activity is allocated to more than 115 statutorily defined funds, such as the General Fund (for general government operations), the Commonwealth Transportation Fund (for transportation-related activity), State Lottery Fund, Federal Grants Fund, and agency fund.
"revenue_class_name", -- A more detailed classification of revenue types within revenue categories, such as sales taxes, income taxes, corporate taxes, fees, agency fund receipts, State Lottery revenues, and reimbursement for state services. There are more than 60 revenue class categories in this dataset.
"revenue_collected",
"fiscal_period_month",
"sub_fund_name",
"department_name", -- A Department is an entity of state government with a specific mission, established by the legislature, which may either report to cabinet-level units of government, known as executive offices or secretariats, or be independent divisions or departments. Each department has an assigned three-letter code in the accounting system; for example, the Office of the Comptroller is CTR.
"trans_no",
"fund_number_fund_name",
"department_code_department",
"revenue_source_revenue_source",
"fiscal_period",
"fund_category_name", -- There are four “Fund Categories” by which revenues are classified: (1) Budgeted Funds, where the revenue funds spending subject to the state’s annual appropriations process; (2) Non Budgeted Special Revenue Funds, were dedicated revenue streams fund spending that is not subject to the annual appropriations process, and the dedicate funding source is established in General Law; (3) Trust and Agency Funds, where the revenue is deposited in accounts and the Commonwealth acts as a trustee on behalf of another party or the state acts as a collection agent for another party, most often for local governments in collecting tax revenues; (4) Higher Education Non-Appropriation Funds, where the Commonwealth’s higher education institutions record tuition and fee revenues in their own delegated accounting systems, but which are reported in the Commonwealth’s accounting system for informational purposes.
"sub_fund",
"cabinet_name", -- A Secretariat (also known as Cabinet) is defined as an executive office that reports to the Governor. Note: In CTHRU, Cabinet/Secretariat also includes offices that do not report to the Governor, such as constitutional offices (e.g., Office of the Treasurer), and independent agencies (e.g., Office of the Comptroller). Executive Departments usually report to Secretariats. For example, the Executive Office of Health and Human Services (EHS) is a Secretariat and the Department of Public Health is a Department within that Secretariat.
"department_code", -- A Department is an entity of state government with a specific mission, established by the legislature, which may either report to cabinet-level units of government, known as executive offices or secretariats, or be independent divisions or departments. Each department has an assigned three-letter code in the accounting system; for example, the Office of the Comptroller is CTR.
"revenue_source",
"revenue_source_name"
FROM
"cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi:latest"."commonwealth_revenue_collections"
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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi 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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi: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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxiCheckout 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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi:latestThis will download all the objects for the latest tag of cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi 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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi: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 cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi: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, cthru-data-socrata/commonwealth-revenue-collections-kcy7-ivxi is just another Postgres schema.