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 annual_city_council_report_on_eligible_list table in this repository, by referencing it like:
"cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9:latest"."annual_city_council_report_on_eligible_list"or in a full query, like:
SELECT
":id", -- Socrata column ID
"agency_desc", -- The name of the agency
"cns_restored_cnt", -- The number of persons restored to lists, by the appointing agency, after having been removed and previously recorded as considered and not selected (CNS)
"dlx_cnt", -- # of candidates whose declination is based on location of the vacancy on the basis of borough ("DLX")
"list_est_date", -- The date on which an eligible list is made available for certification to agencies to consider an eligible candidate for appointment.
"list_div_code", -- A three (3) digit number used to identify an agency (For Transit Promotion lists only).
"aac_cnt", -- # of candidates removed from list due to appointment from Agency Certification ("AAC") Pool
"ova_cnt", -- # of candidates who were removed from list due to being overage for the position ("OVA")
"list_agency_code", -- A three (3) digit number used to identify an agency
"dea_cnt", -- # of candidates removed from list because they declined appointment ("DEA")
"fra_cnt", -- # of candidates who were removed from list due to failing to report or who declined after accepting appointment ("FRA")
"unf_cnt", -- # of candidates who were removed from list due to being underage at the time of filing ("UNF")
"rli_cnt", -- # of candidates who were removed from list due to reporting late for interview ("RLI")
"list_title_code", -- A five (5) digit number that corresponds to and represents a civil service title.
"fri_cnt", -- # of candidates who were removed from list due to failing to report for investigation ("FRI")
"exam_no", -- A four (4) digit number that identifies a civil service examination.
"appt_cnt", -- The number of persons appointed or promoted from each eligible list and the agencies to which such appointments or promotions were made
"o_c_or_prom", -- A descriptive name that identifies a civil service list type.
"frm_cnt", -- # of candidates who were removed from list due to failing to report for medical ("FRM")
"frp_cnt", -- # of candidates who were removed from list due to failing to report for psychological exam ("FRP")
"tin_cnt", -- # of candidates who were removed from list due to declination - temporary inability to accept ("TIN")
"dce_cnt", -- # of candidates removed from list because they were deceased ("DCE")
"ftr_cnt", -- # of candidates who were removed from list due to failing to report for interview ("FTR")
"aol_cnt", -- # of candidates removed from list due to appointment from another promotion list or unique open competitive list
"nfp_cnt", -- # of candidates who were removed from list due to undeliverable mailing address ("NFP")
"nle_cnt", -- # of candidates who were removed from list due to no longer being employed/not employed in lower titles ("NLE")
"title_description", -- A descriptive name that identifies a civil service title.
"elig_restored_cnt", -- The number of persons restored to a list following their removal from a list by their own action
"frh_cnt", -- # of candidates who were removed from list due to failing to report for physical ("FRH")
"cns_cnt" -- The number of persons who, during the reporting year, were considered and not selected (CNS) three times from promotion lists
FROM
"cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9:latest"."annual_city_council_report_on_eligible_list"
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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9 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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9: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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9Checkout 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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9:latestThis will download all the objects for the latest tag of cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9 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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9: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 cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9: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, cityofnewyork-us/annual-city-council-report-on-eligible-list-qjzt-ytn9 is just another Postgres schema.