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 collin_cad_appraisal_data table in this repository, by referencing it like:
"texas-gov/collin-cad-appraisal-data-nne4-8riu:latest"."collin_cad_appraisal_data"or in a full query, like:
SELECT
":id", -- Socrata column ID
"propyear", -- Property Appraisal Year
"propid", -- Property ID (short account number aka Key ID)
"geoid", -- Geographical ID (long account number)
"proptype", -- Property Type (BPP, Manufactured Home, Mineral, Real)
"propsubtype", -- Property Sub Type (BPP, Commercial, Land, Residential)
"propcategorycode", -- PTAD Category Code (see code-file list)
"propusecode", -- Property Use Code
"mapid", -- Map ID
"nbhdcode", -- Neighborhood Code
"marketareacode", -- Market Area Code
"legalabssubcode", -- Abstract/Condo/Subdivision/Mobile Home Park Code
"legalabssubname", -- Abstract/Condo/Subdivision/Mobile Home Park Name
"legalabssubblock", -- Block/Building
"legalabssublot", -- Tract/Lot/Space/Unit
"legaldescription", -- Legal Description
"dbaname", -- "Doing Business As" Name
"compropflag", -- Commercial Property Flag (T/F)
"udipropflag", -- Undivided Interest Property Flag (T/F)
"udigroupid", -- Undivided Interest Group ID
"udiinterestpct", -- Undivided Interest Ownership Percentage
"commoninterestpct", -- Common Elements Interest Percentage
"ecogroupid", -- Economic Group ID
"ecogroupgba", -- Economic Group Gross Building Area
"ecogroupnra", -- Economic Group Net Rentable Area
"propsplitfrompid", -- Property Split-From Property ID
"propcreatedate", -- Property Create Date
"entitycodes", -- All Entity Codes (concatenated; see code-file list)
"entityschoolcode", -- School Entity Code (see code-file list)
"entitycitycode", -- City Entity Code (see code file-list)
"entitymud", -- MUD Entity Flag (T/F)
"entitytif", -- Tax Increment Fund/Reinvestment Zone Flag (T/F)
"entitysbcl", -- Split -By County Line Flag (T/F)
"situsbldgnum", -- Situs Building Number
"situsstreetprefix", -- Situs Street Prefix
"situsstreetname", -- Situs Street Name
"situsstreetsuffix", -- Situs Street Suffix
"situsunit", -- Situs Unit
"situscity", -- Situs City Name
"situszip", -- Situs Zip-Code
"situsconcat", -- Situs Address (concatenated, full)
"situsconcatshort", -- Situs Address (concatenated, no city state zip)
"ownerid", -- Property Owner ID
"ownername", -- Owner Name (primary/line 1)
"ownernameaddtl", -- Owner Name (additional/line 2)
"owneraddrline1", -- Owner Mailing Address Line 1
"owneraddrline2", -- Owner Mailing Address Line 2
"owneraddrcity", -- Owner Mailing Address City
"owneraddrstate", -- Owner Mailing Address State
"owneraddrzip", -- Owner Mailing Address Zip-Code (5+4)
"owneraddrcountry", -- Owner Mailing Address Country Code
"taxagentid", -- Tax Agency ID
"taxagentname", -- Tax Agency Name
"deedtypecd", -- Last Deed Type Code (see code-file list)
"deednum", -- Last Deed County Clerk Instrument Number
"deedbook", -- Last Deed County Clerk Book Number
"deedpage", -- Last Deed County Clerk Page Number
"deedeffdate", -- Last Deed Effective Date
"deedfiledate", -- Last Deed County Clerk File Date
"imprvyearbuilt", -- Main Improvement Year Built
"imprvclasscd", -- Main Improvement Class Code
"imprvmainarea", -- Total Improvement Main Area (aka living area)
"imprvunits", -- Total Improvement Number of Units (if available)
"imprvpoolflag", -- Pool Exists Flag (T/F)
"imprvcategorycodes", -- Improvement PTAD Category Codes (concatenated; see code-file list)
"landtypecode", -- Predominant Land Type Code (see code-file list)
"landsizeacres", -- Total Land Size Acres
"landsizesqft", -- Total Land Size Square Feet
"landagacres", -- Total Land Agricultural Appraisal Acres
"landcategorycodes", -- Land PTAD Category Codes (concatenated; see code-file list)
"exemptcodes", -- Exemption Codes (concatenated; excluding age-related exemptions)
"exempthmstdflag", -- Homestead Exemption Flag (T/F)
"protestcode", -- ARB Protest Indicator (A=Active, C=Closed, H=Heard by ARB)
"propstatus", -- Property Status (InProgress, Preliminary, Certified)
"currvalyear", -- Current Year
"currvalimprv", -- Current Year Improvement Value
"currvalland", -- Current Year Land Value
"currvalmarket", -- Current Year Market Value
"currvalagloss", -- Current Year Ag Loss
"currvalappraised", -- Current Year Appraised Value
"currvalhscaploss", -- Current Year Homestead Cap Loss
"currvalnhscaploss", -- Current Year Non-Homestead Cap Loss
"currvalassessed", -- Current Year Assessed Value
"prevvalyear", -- Previous Year
"prevvalimprv", -- Previous Year Improvement Value
"prevvalland", -- Previous Year Land Value
"prevvalmarket", -- Previous Year Market Value
"prevvalagloss", -- Previous Year Ag Loss
"prevvalappraised", -- Previous Year Appraised Value
"prevvalhscaploss", -- Previous Year Homestead Cap Loss
"prevvalnhscaploss", -- Previous Year Non-Homestead Cap Loss
"prevvalassessed", -- Previous Year Assessed Value
"noticeyear", -- Notice Year
"noticevalimprv", -- Notice Year Improvement Value
"noticevalland", -- Notice Year Land Value
"noticevalmarket", -- Notice Year Market Value
"noticevalagloss", -- Notice Year Ag Loss
"noticevalappraised", -- Notice Year Appraised Value
"noticevalhscaploss", -- Notice Year Homestead Cap Loss
"noticevalnhscaploss", -- Notice Year Non-Homestead Cap Loss
"noticevalassessed", -- Notice Year Assessed Value
"noticedate", -- Notice Date
"datadate" -- Data As-Of Date
FROM
"texas-gov/collin-cad-appraisal-data-nne4-8riu:latest"."collin_cad_appraisal_data"
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 texas-gov/collin-cad-appraisal-data-nne4-8riu 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 texas-gov/collin-cad-appraisal-data-nne4-8riu: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 texas-gov/collin-cad-appraisal-data-nne4-8riuCheckout 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 texas-gov/collin-cad-appraisal-data-nne4-8riu:latestThis will download all the objects for the latest tag of texas-gov/collin-cad-appraisal-data-nne4-8riu 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 texas-gov/collin-cad-appraisal-data-nne4-8riu: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 texas-gov/collin-cad-appraisal-data-nne4-8riu: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, texas-gov/collin-cad-appraisal-data-nne4-8riu is just another Postgres schema.