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 building_permits table in this repository, by referencing it like:
"citydata-mesaaz-gov/building-permits-dzpk-hxfb:latest"."building_permits"or in a full query, like:
SELECT
":id", -- Socrata column ID
"permit_number", -- The case/permit number used to refer to this application or permit record This number consists of: 1) A three-character prefix (BLD or PMT, which means a building permit); 2) A four or two digit year (the year in which the application was made); 3) A hyphen; 4) A five digit sequential number
"offense_witnessed", -- Not used by permits
"public_owned", -- Not used by permits
":@computed_region_c54k_jm6w", -- This column was automatically created in order to record in what polygon from the dataset 'Hexagon 16th Square Mile Project' (c54k-jm6w) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_yvgd_jnii", -- This column was automatically created in order to record in what polygon from the dataset 'Hexagon 8th Square Mile Project' (yvgd-jnii) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_5spd_7gy6", -- This column was automatically created in order to record in what polygon from the dataset 'Mesa Census Tracts To City Boundary v2022' (5spd-7gy6) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"rowid", -- Unique Row Identifier
"street_type", -- The street type of the property address where the construction will take place
"unit_num", -- The Unit Number of Property Address
"council_district", -- City Council District Associated with Property Address
"issued_year", -- The year the permit was issued by the City of Mesa.
"issued_month", -- The month the permit was issued by the City of Mesa
"finaled_year", -- The year the final inspection was completed.
"finaled_month", -- The month the final inspection was completed.
"permit_year", -- The year when the permit was issued by City of Mesa
"status", -- The current status of the permit, which is one of these: Under Review, Approved, Issued, Finaled (meaning project is completed), Void
"description_of_work", -- A brief description of the work to be done, sometimes includes location information
"permit_type", -- Type of permit: COM = Commercial construction; RES = Residential construction; SVC = Application for Service(s)
"icc_value", -- The dollar value of the work to be done based on valuation rates furnished by the International Code Council (ICC)
"contractor_state", -- The state of the contractor associated with the permit, if any
"contractor_zip", -- The zip code of the contractor associated with the permit, if any
"contractor_phone", -- The phone number of the contractor associated with the permit, if any
"number_of_dwellings", -- The number of buildings considered to be dwellings for this project.
"number_of_dwelling_units", -- The number of units or apartments for this project.
"new_residential_permit", -- 'Y' if this is a permit for a new residential building, or 'N' if otherwise.
"permit_module", -- Record Module (e.g. Permits, Licences etc)
"record_type", -- Type of Permit (e.g. Residential, Commericial, Sign)
"permits_id", -- Permits ID (Internal Use)
"update_date", -- Date Updated
"application_class", -- Indicates whether or not the application is finished
"short_notes", -- Notes entered by the applicant
"created_by", -- UserID of person who created the record
"product_name_identifier", -- Tracks where the application's information was entered
"total_fee_invoiced", -- Total fees paid
"balance", -- Remaining balance to be paid
"booking", -- Not used by permits
"infraction", -- Not used by permits
"misdemenor", -- Not used by permits
"assigned_date", -- Date Assigned
"assigned_department", -- Department the workflow is assigned to
"completed_date", -- Date Completed
"closed_by_department", -- Department of the staff member who closed the permit
"completed_by_department", -- Department of the staff member who completed the permit
"closed_by_user", -- UserID of person who closed the permit
"location", -- Geocoded location associated with this permit.
"street_direction", -- The street direction of the property address where the construction will take place
"cofo_date", -- Date Certificate of Occupancy issued
"cofo_year", -- Year of Certificate of Occupancy issued
"parcel_number", -- The primary parcel number associated with this permit This number is assigned by Maricopa County and consists of: Book Number (first three characters); Page Number (next two characters); Parcel Number (last three or four characters)
"issued_date", -- The date the permit was issued by the City of Mesa, allowing construction to begin
"total_square_feet", -- The total square footage for work being accomplished by this permit
"reported_date", -- Reported Date
"street_name", -- The street name of the property address where the construction will take place
"contractor_email", -- The email address of the contractor associated with the permit, if any
"total_fee_assessed", -- Total fees assessed
"reported_channel", -- Channel used to report (e.g. telephone - Used for Code, not permits)
"created_by_cloning", -- Indicates record created by cloning another record (used with subdivisions)
"contractor_city", -- The city of the contractor associated with the permit, if any
"fiscalyear",
"street_number", -- The street number of the property address where the construction will take place
"fiscal_year", -- The Fiscal Year in which the permit was issued.
"cofo_month", -- Month Certificate of Occupancy issued
"status_date", -- Date status changed
"tracking_id", -- Internal Tracking identifier assigned by the system
"contractor_license", -- The contractor license number associated with the permit, if any
"application_name", -- Application or Job Name as identified by applicant
"property_address", -- The street address where the construction will take place
"finaled_date", -- The date the final inspection was completed. There can be NO work done after this date.
"job_value", -- Job value, Total Value or Total Project Valuation as entered by the applicant
"type_of_work", -- A more specific description of the Use
"contractor_name", -- The name of the contractor associated with the permit, if any
"contractor_address", -- The address of the contractor associated with the permit, if any
"applicant", -- The name of the person that applied for the permit
"record_id", -- Internal Record identifier assigned by the system
"opened_date", -- Date record opened (aka File Date)
"closed_date", -- Date Closed
"assigned_user", -- UserID of person assigned to the permit
"latitude", -- The latitude for the location associated with this permit
"longitude" -- The longitude for the location associated with this permit
FROM
"citydata-mesaaz-gov/building-permits-dzpk-hxfb:latest"."building_permits"
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/building-permits-dzpk-hxfb 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/building-permits-dzpk-hxfb: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/building-permits-dzpk-hxfb" \
--handler-options '{
"domain": "citydata.mesaaz.gov",
"tables": {
"building_permits": "dzpk-hxfb"
}
}'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/building-permits-dzpk-hxfb is just another Postgres schema.