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_new_construction table in this repository, by referencing it like:
"cambridgema-gov/building-permits-new-construction-9qm7-wbdc:latest"."building_permits_new_construction"or in a full query, like:
SELECT
":id", -- Socrata column ID
":@computed_region_rffn_qbt6",
"plumbing_cost", -- Plumbing Cost of Construction
"gas_cost", -- Gas Cost of Construction
"hvac_cost", -- HVAC Cost of Construction
"electrical_cost", -- Electrical Cost of Construction
"building_cost", -- Building Cost of Construction
"right_of_way", -- Will the proposed work result in a new, abandoned or modified curb cut into the public right-of-way?
"air_cafe_windows", -- Will the food establishment include open air cafe windows?
"vehicle_parking_spaces", -- Number of Proposed Off-Street Vehicle Parking Spaces
"architect_firm",
"property_use_other", -- Zoning I: Describe current property use (other)
"debris_removal_location", -- Construction debris will be disposed at/by
"debris_removal_date", -- Construction Debris Removal Completion Date
"dumpster_no", -- Construction: Cambridge Dumpster Licence #
"proposed_count_of_dwelling", -- Zoning I: Proposed number of dwelling units
"issue_date", -- Date permit was issued
"submit_date", -- Date application for permit was submitted
"longitude",
"geocoded_column_address",
"address",
"construction_dewatering", -- Will the proposed work require construction dewatering during any phase of the project?
"long_term_bike_parking", -- Number of Proposed Off-Street Bicycle Parking Spaces (Long Term)
"construction_type", -- Proposed: Building Construction Type
"bza_number", -- Special: Board of Zoning Appeal (BZA) Case Number
"method_of_removal", -- Construction: Method of Removal
"short_term_bike_parking", -- Number of Proposed Off-Street Bicycle Parking Spaces (Short Term)
"description_of_work", -- Detailed Description of Work
"building_height", -- Proposed: Building Height (feet)
"geocoded_column_state",
"stories_above_grade", -- Proposed: Number of Stories (Above Grade)
"board_special_permit", -- Special: Is this application subject to a Planning Board Special Permit?
"final_cost", -- Final Cost of Construction
"proposed_loading_bays", -- Number of Proposed Loading Bays
"gross_square_footage", -- Proposed: Gross Square Footage
"geocoded_column", -- Address geocoded so that it can be used to create a map on the open data portal
"proposed_building_use",
"other_cooking_equipment", -- Food Est: Other Cooking Equipment
"employment_arrangement", -- Select the option that best describes you or your company's employment arrangement.
"roof_foundation_drain", -- Will the proposed work result in the addition or alteration of a roof or foundation drain that discharges to the City?
"new_food_establishment", -- Will the proposed work result in a new food establishment?
"finish_materials", -- Food Est: Describe the finish materials for the floor, walls, ceiling and cove
"special_permit_number", -- Special: Planning Board Special Permit Number
"proposed_property_use", -- Zoning I: Proposed Property Use
"cooking_type", -- Cooking Equipment Type
"building_removal", -- Will removal of buildings be required for this construction?
"id", -- Permit ID
"geocoded_column_city",
"total_cost_of_construction",
"basement_plumbing_fixture", -- Will the proposed work result in the addition or replacement of a basement plumbing fixture?
"certificate", -- Certificate of Occupancy Required
"temporary_dumpster_permit", -- Would you like to apply for a temporary dumpster permit as part of this building permit application?
"latitude",
"geocoded_column_zip",
"impervious_cover", -- Will the proposed work result in an increase to the property’s impervious cover?
"appeal_bza_case", -- Special: Is this application subject to a Board of Zoning Appeal (BZA) Case?
"proposed_loading_facilities", -- Number of Proposed Loading Facilities
"status", -- Status of application
"current_property_use", -- Zoning I: Current Property Use
":@computed_region_swkg_bavi",
":@computed_region_v7jj_366k",
":@computed_region_guic_hr4a",
":@computed_region_e4yd_rwk4",
"storm_sewer_connections" -- Will the proposed work result in new, abandoned, or replaced sanitary storm sewer connections?
FROM
"cambridgema-gov/building-permits-new-construction-9qm7-wbdc:latest"."building_permits_new_construction"
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 cambridgema-gov/building-permits-new-construction-9qm7-wbdc 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 cambridgema-gov/building-permits-new-construction-9qm7-wbdc: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 cambridgema-gov/building-permits-new-construction-9qm7-wbdcCheckout 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 cambridgema-gov/building-permits-new-construction-9qm7-wbdc:latestThis will download all the objects for the latest tag of cambridgema-gov/building-permits-new-construction-9qm7-wbdc 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 cambridgema-gov/building-permits-new-construction-9qm7-wbdc: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 cambridgema-gov/building-permits-new-construction-9qm7-wbdc: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, cambridgema-gov/building-permits-new-construction-9qm7-wbdc is just another Postgres schema.