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 dwr_well_application_permit table in this repository, by referencing it like:
"colorado-gov/dwr-well-application-permit-wumm-7awb:latest"."dwr_well_application_permit"or in a full query, like:
SELECT
":id", -- Socrata column ID
"idkey", -- IDKey
"yield", -- Yield in gallons per minute
"bottom_perforated_casing", -- Depth from surface to bottom of perforated casing (feet)
"top_perforated_casing", -- Depth from surface to top of perforated casing (feet)
"associated_aquifers", -- Aquifer(s) associated with the Well
"well_plugged", -- Date the Well was plugged and abandoned or DWR was notified
"pump_installed", -- Date the pump was installed or DWR was notified of the installation
"well_constructed", -- Date the Well was constructed or DWR was notified of the construction
"permit_expires", -- Date the Well permit will expire if not constructed
"_1st_beneficial_use", -- Date of first beneficial use or DWR was notified of first beneficial use
"permit_issued", -- Date Well permit was issued
"permit_category", -- Permit Category
"city", -- City
"parcel_name", -- Parcel Name
"location_accuracy", -- Accuracy of location coordinates
"longitude", -- Longitude (decimal degrees)
"coordsns", -- Distance from North/South section line (feet)
"section", -- Legal location - section number
"range", -- Legal location - range
"county", -- County where the Well is located
"wd", -- DWR Water District
"contact_name", -- Contact(s) associated with Well
"current_status", -- Indicates the current application or physical status of the application/well permit based on entered information
"permit", -- Concatenation of permit number, suffix code, and replacement code
"pm", -- Principal Meridian
"management_district", -- Thirteen local districts, within the Designated Basins, with additional administrative authority
"modified", -- Last date time that this record was modified in the DWR database
"wdid", -- DWR unique structure identifier
"static_water_level_date", -- Static Water Level Date
"static_water_level", -- Static Water Level
"postal_code", -- Postal Code
"latitude", -- Latitude (decimal degrees)
"utm_x", -- The x (Easting) component of the Universal Transverse Mercator system. (Zone 12, NAD83 datum)
"coordsew", -- Distance from East/West section line (feet)
"township", -- Legal location - Township number and direction
"designated_basin", -- Designated basin where Well is located
"receipt", -- Permit application receipt number
"well_depth", -- Completed depth of Well (ft)
"stateorprovince", -- State
"address", -- Address of Well
"utm_y", -- The y (Northing) component of the Universal Transverse Mercator system. (Zone 12, NAD83 datum)
"associated_case_numbers", -- Water court case number(s) associated with water right
"elev", -- Surface elevation at the location of the Well (feet above mean sea level)
"associated_uses", -- Decreed uses associated with the Well
"location_address",
"location", -- Latitude/Longitude where the Well is located
"denver_basin_aquifer", -- Denver Basin Aquifer
"location_state",
"location_type", -- Location Type
"coordsns_dir", -- Direction of measurement from North/South section line
"coordsew_dir", -- Direction of measurement from East/West section line
"q40", -- Legal location - 40 acre quarter section
"div", -- DWR Water Division
"q160", -- Legal location - 160 acre quarter section
"location_zip",
"location_city",
"q10", -- Legal location - 10 acre quarter section
":@computed_region_nku6_53ud",
"more_information" -- Hyperlink to more information about the Well Application/Permit
FROM
"colorado-gov/dwr-well-application-permit-wumm-7awb:latest"."dwr_well_application_permit"
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 colorado-gov/dwr-well-application-permit-wumm-7awb 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 colorado-gov/dwr-well-application-permit-wumm-7awb: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 colorado-gov/dwr-well-application-permit-wumm-7awbCheckout 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 colorado-gov/dwr-well-application-permit-wumm-7awb:latestThis will download all the objects for the latest tag of colorado-gov/dwr-well-application-permit-wumm-7awb 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 colorado-gov/dwr-well-application-permit-wumm-7awb: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 colorado-gov/dwr-well-application-permit-wumm-7awb: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, colorado-gov/dwr-well-application-permit-wumm-7awb is just another Postgres schema.