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 city_revenues table in this repository, by referencing it like:
"citydata-mesaaz-gov/city-revenues-ntuh-v7ru:latest"."city_revenues"or in a full query, like:
SELECT
":id", -- Socrata column ID
"record_id", -- Unique Record Identifier that is being used for sorting and grouping purposes
"document_type_name", -- The type of document the transaction was recorded in the accounting system
"reporting_code_name", -- A reporting mechanism used to track the expenditures related to a specific event or item. Examples are shows at the Mesa Arts Center and park expenses.
"reporting_code", -- The number assigned to a reporting mechanism used to track the expenditures related to a specific event or item. Examples are shows at the Mesa Arts Center and park expenses.
"unit_name", -- The organizational unit within the department that benefited from the transaction. Examples include Planning,Development Services, Energy Resources, Electric Utility and Gas Utility.
"unit_code", -- The number assigned to the organizational unit within the department that benefited from the transaction
"phase_name", -- A project is split into phases which generally represent Pre-design/Design/Construction or may be split into Purchases (where no construction is involved in the acquisition of the asset)
"program_name", -- A program represents a smaller segment of a project the City is working on For example, renovating a Park would be a major program, installing the bathroom would be a program
"program_code", -- The number assigned to a program
"major_program_name", -- A project the City is working on Generally, a major program is created to capture all of the costs of creating a new or improving an existing asset before the asset is placed in service Major programs may also track costs related to a grant awarded to the City
"major_program_code", -- The number assigned to a project
"legal_name", -- Legal Name of the revenue source
"amount", -- The Amount of the transaction
"revenue_name", -- The type of revenue received In the private sector, this may be called a General Ledger account, however in the Government sector, these are most often referred to as Revenue Sources. Examples include City Sales Tax, Highway User Tax and State Grants.
"revenue_code", -- The number assigned to the type of revenue received In the private sector, this would be called a General Ledger account number, however in the Government sector, these are most often referred to as Revenue Source codes
"revenue_type_name", -- A grouping of revenues into Types on the chart of accounts Types are then grouped into categories
"revenue_type_code", -- The number assigned to the Revenue Type on the chart of accounts
"revenue_category_name", -- The grouping of revenue types into categories on the chart of accounts Category examples include Taxes and Intergovernmental
"sub_activity_name", -- Some activities are broken down into sub-activities for reporting and analysis purposes
"sub_activity_code", -- The number assigned to a sub-activity
"activity_name", -- The activity the department was engaged in that led to the transaction Activities are generally recurring activities such as accounting, inspections or planning
"activity_code", -- The number assigned to the activity the department was engaged in that led to the transaction
"core_business_proces_name", -- A collection of related programs and services that are designed and managed to achieve a common outcome or set of outcomes These include Patrol, Metro, and Criminal Investigations
"core_business_process_code", -- The number assigned to a collection of related programs and services that are designed and managed to achieve a common outcome or set of outcomes
"service_level_name", -- A group of Core Business Processes related by a common purpose (mission, outcomes, and expected performance) This level of structure is optional depending on departmental needs. Examples include Operations Bureau and Investigations Bureau.
"service_level_code", -- The number assigned to a group of Core Business Processes related by a common purpose (mission, outcomes, and expected performance) This level of structure is optional depending on departmental needs
"business_objective_name", -- A major line of business that aligns with one or more of the purpose; and defines where the City allocates its resources. Examples include Fleet Services and Economic Development.
"business_objective_code", -- The number assigned to a major line of business that aligns denotes a primary public purpose; and defines where the City allocates its resources
"department_name", -- The Department that benefited from the transaction
"sub_fund_name", -- The breakdown of a fund based on purpose, classification, and other specific characteristics
"fund_name", -- The governmental segment that benefited from the transaction. Examples include Cemetery, Transit and Arts and Culture.
"fund_code", -- The number assigned to the governmental segment that benefited from the transaction
"date", -- The time and date the data was last updated from the accounting system
"fiscal_month_name", -- Transaction month in the fiscal year
"accounting_period", -- The accounting period the transaction was recorded The City's accounting year runs from July 1 to June 30, where July is accounting period 1
"accounting_fiscal_year", -- The Accounting Fiscal Year the Document was created. The Accounting Fiscal year is determined by rules of recognition of liability or revenue and can differ from the Budget Fiscal Year The City's Fiscal Year is from July 1 to June 30.
"row_id", -- Unique identifier for each row of the dataset
"document_type_code", -- The number assigned to the type of document the transaction was recorded in the accounting system
"document_id", -- The number assigned to the transaction by the accounting system
"sub_fund_code", -- The numbers assigned for the breakdown of a fund based on purpose, classification, and other specific characteristics
"calendar_year", -- Calendar year of the transaction
"as_phase_code", -- The number assigned to a phase of a project
"appropriation_code", -- The number assigned to the type of appropriation of the transaction
"department_code", -- The number assigned to the Department that benefited from the transaction
"revenue_category_code", -- The number assigned to the category of revenue on the chart of accounts
"appropriation_name", -- The type of appropriation of the transaction These will either be the Base Operating Budget or a Capital Improvement Project
"fiscal_year" -- Fiscal year of the transaction
FROM
"citydata-mesaaz-gov/city-revenues-ntuh-v7ru:latest"."city_revenues"
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 citydata-mesaaz-gov/city-revenues-ntuh-v7ru with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at citydata.mesaaz.gov. When you querycitydata-mesaaz-gov/city-revenues-ntuh-v7ru: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 citydata.mesaaz.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 \
"citydata-mesaaz-gov/city-revenues-ntuh-v7ru" \
--handler-options '{
"domain": "citydata.mesaaz.gov",
"tables": {
"city_revenues": "ntuh-v7ru"
}
}'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, citydata-mesaaz-gov/city-revenues-ntuh-v7ru is just another Postgres schema.