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 2018_prek_school_directory table in this repository, by referencing it like:
"cityofnewyork-us/2018-prek-school-directory-xck4-5xd5:latest"."2018_prek_school_directory"or in a full query, like:
SELECT
":id", -- Socrata column ID
"census_tract", -- The Census Tract field indicates the U.S. Census Tract where the building is located.
"bin", -- The BIN (Building Identification Number) is a unique identifier for each building in the City.
"council_district", -- The Council District field indicates the New York City Council District where the building is located.
"community_board", -- The Community Board field indicates the New York City Community District where the building is located.
"phone", -- School's phone number
"programname3", -- Designates whether the third program at the school (if applicable) is full-day, half-day, 5 hour, or dual language.
"postcode", -- Zipcode where the building is located
"pkc_indistrict_all", -- For District programs: designates whether all in-district students received offers last year
"district_outdistrict_2", -- For District programs: designates whether no in-district students received offers last year
"nyceec_siblings_some", -- For NYCEECs: designates whether some current students received offers last year
"income_flg", -- Flag for programs that may have income or other eligibility requirements.
"nyceec_targetlang", -- For NYCEECs and are Enhanced Language programs: designates whether all students that speak the target language received offers last year
"nyceec_current_some", -- For NYCEECs: designates whether some current students received offers last year
"nyceec_services_some", -- For NYCEECs: designates whether some students receiving social services received offers last year
"uniforms", -- Flag for programs that have a uniform requirement
"nyceec_services_all", -- For NYCEECs: designates whether all students receiving social services received offers last year
"nyceec_targetlang_1", -- For NYCEECs and are Enhanced Language programs: designates whether some students that speak the target language received offers last year
"programcode2", -- Code families use on the application to apply to that specific program (affiliated with programname2).
"contact_email", -- The email of the contact person at the school
"longitude", -- Longitude of the building's location.
"enhancedlang_note", -- Designates whether a program is an Enhanced Language program. Identifies the target language.
"subway_stop", -- Subway lines near the school
"bus", -- Bus lines near the school
"halfday_offers", -- A note explaining that the "Who Got Offers" chart does not apply to half-day programs.
"lpga", -- A note explaining who received offers last year for programs with unique priority structures or for those in choice districts. Programs new to the 2018 Pre-K Application are also noted here.
"nyceec_siblings_none", -- For NYCEECs: designates whether no siblings received offers last year
"pkc_indistrict_some", -- For District programs: designates whether some in-district students received offers last year
"pkc_outdistrict_none", -- For District programs: designates whether no out-of-district students received offers last year
"nyceec_current_none", -- For NYCEECs: designates whether no current students received offers last year
"district_otherzone_2", -- For District programs: designates whether some zoned students received offers last year
"pkc_indistrict_none", -- For District programs: designates whether no in-district students received offers last year
"nyceec_current_all", -- For NYCEECs: designates whether all current students received offers last year.
"programcode1", -- Code families use on the application to apply to that specific program (affiliated with programname1).
"play", -- Designates the type of playspace a school has available to students and whether the space is indoor, outdoor, onsite or offsite
"final_address", -- School's address
"bbl", -- The BBL (Borough, Block, and Lot) is a unique identifier for each tax lot in the City.
"nyceec_others_all", -- For NYCEECs: designates whether all other students received offers last year
"flexschedule", -- Designates whether a program may have a flexible scheduling policy.
"latitude", -- Latitude of the building's location.
"earlydropoff", -- Time a program starts early dropoff.
"nyceec_targetlang_2", -- For NYCEECs and are Enhanced Language programs: designates whether no students that speak the target language received offers last year
"nyceec_siblings_all", -- For NYCEECs: designates whether all siblings received offers last year
"nyceec_services_none", -- For NYCEECs: designates whether no students receiving social services received offers last year
"programcode3", -- Code families use on the application to apply to that specific program (affiliated with programname3).
"district_indistrict", -- For District programs: designates whether all in-district students received offers last year
"district_outdissibs", -- For District programs: designates whether all out-of-district siblings received offers last year
"hours", -- Program hours
"accessibility", -- Designates the program's level of accessibility.
"pkc_outdistrict_all", -- For District programs: designates whether all out-of-district students received offers last year
"rezoning", -- Designates district schools that could potentially be impacted by a rezoning proposal.
"latepickup", -- Time a program ends late pickup.
"diversity", -- Designates whether a program is part of the Diversity in Admissions pilot.
"specialpriority", -- Describes the priority structures for programs with unique admissions priorities. This also flags programs located in choice districts.
"pkc_outdistrict_some", -- For District programs: designates whether some out-of-district students received offers last year
"district_outdistrict", -- For District programs: designates whether all in-district students received offers last year
"district_outdissibs_2", -- For District programs: designates whether no out-of-district siblings received offers last year
"district_outdissibs_1", -- For District programs: designates whether some out-of-district siblings received offers last year
"district_3", -- For District programs: designates whether no in-district siblings received offers last year
"district_2", -- For District programs: designates whether some in-district siblings received offers last year
"district_1", -- For District programs: designates whether all in-district siblings received offers last year
"district_otherzone", -- For District programs: designates whether all in-district siblings received offers last year
"district_zonedsib_2", -- For District programs: designates whether no zoned students received offers last year
"nyceec_others_none", -- For NYCEECs: designates whether no other students received offers last year
"programname2", -- Designates whether the second program at the school (if applicable) is full-day, half-day, 5 hour, or dual language.
"programname1", -- Designates whether the first program offered at the school is full-day, half-day, 5 hour, or dual language.
"meals", -- Designates which meals are provided to students during the school day. Values can be all, none or some of the following: breakfast, lunch, snack(s)
"website", -- School website
"contact_name", -- The name of the contact person at the school
"district_outdistrict_1", -- For District programs: designates whether some in-district students received offers last year
"prek_type", -- Pre-K program type
"district", -- Community School District school is located
"borough", -- Borough where school is located
"locationname", -- School's name
"schooldbn", -- DBN (District Borough Number): code used by the NYC Department of Education to uniquely identify schools
"nta", -- The Neighborhood Tabulation Area field indicates the New York City Neighborhood area where the building is located.
"district_otherzone_1", -- For District programs: designates whether some in-district siblings received offers last year
"district_zonedsib_1", -- For District programs: designates whether some zoned siblings received offers last year
"district_indistrict_2", -- For District programs: designates whether no out-of-district siblings received offers last year
"iepnote", -- A note that prompts families of students with particular IEP recommendations to contact the program.
"magnet", -- Designates whether a program is a magent program. Describes the curricular focus of that magent program.
"district_indistrict_1", -- For District programs: designates whether some in-district students received offers last year
"district_zonedsib", -- For District programs: designates whether all zoned siblings received offers last year
"seats", -- The number of full-day, half-day and 5 hour seats at program(s) last year.
"singlegender", -- Flag for programs that may have some single-gender classrooms or are single-gender programs
"nyceec_others_some" -- For NYCEECs: designates whether some other students received offers last year
FROM
"cityofnewyork-us/2018-prek-school-directory-xck4-5xd5:latest"."2018_prek_school_directory"
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/2018-prek-school-directory-xck4-5xd5 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cityofnewyork.us. When you querycityofnewyork-us/2018-prek-school-directory-xck4-5xd5: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 data.cityofnewyork.us, 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 \
"cityofnewyork-us/2018-prek-school-directory-xck4-5xd5" \
--handler-options '{
"domain": "data.cityofnewyork.us",
"tables": {
"2018_prek_school_directory": "xck4-5xd5"
}
}'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, cityofnewyork-us/2018-prek-school-directory-xck4-5xd5 is just another Postgres schema.