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 cdph_mental_health_resources_deprecated_november table in this repository, by referencing it like:
"cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym:latest"."cdph_mental_health_resources_deprecated_november"or in a full query, like:
SELECT
":id", -- Socrata column ID
"age_range_served", -- Ages Served by Site/Facility
"ticc_areas_served", -- Trauma-Informed Center of Care Service Area
"service_request_phone", -- Service Request Phone #
"site_type", -- Type of Health Center
":@computed_region_rpca_8um6", -- This column was automatically created in order to record in what polygon from the dataset 'Boundaries - ZIP Codes' (rpca-8um6) the point in column 'location_2' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"evening_hours_availability", -- Availability of Evening Services
":@computed_region_vrxf_vc4k", -- This column was automatically created in order to record in what polygon from the dataset 'Community Areas' (vrxf-vc4k) the point in column 'location_2' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_6mkv_f3dw", -- This column was automatically created in order to record in what polygon from the dataset 'Zip Codes' (6mkv-f3dw) the point in column 'location_2' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_bdys_3d7i", -- This column was automatically created in order to record in what polygon from the dataset 'Census Tracts' (bdys-3d7i) the point in column 'location_2' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_43wa_7qmu", -- This column was automatically created in order to record in what polygon from the dataset 'Wards' (43wa-7qmu) the point in column 'location_2' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"all_community_areas_served", -- All Community Areas Served by Site
"first_episode_psychosis_programming_detail", -- First Episode Psychosis Programming - Detail
"crisis_intake_phone", -- Crisis Intake Phone #
"crisis_services", -- Availability of Crisis Services
"behavioral_services_types", -- Types of Behavioral Health Services Offered
"location", -- The location of the clinic in a format that allows for creation of maps and other geographic operations on this data portal.
"address", -- Facility Address
"organization", -- Organization or Agency
"crisis_services_types", -- Types of Crisis Services Offered
"hours", -- Facility Hours
"language_line_availability", -- Availability of Language-Line Services for Non-English Speaking Patients
"other_languages", -- Availability of Non-English Languages for Offered Services
"telehealth_services_availability", -- Availability of Telehealth Services
"bhs_service_availability_primary_care", -- Restriction of Behavioral Health Services For Primary Care Patients Only
"primary_care_availability", -- Availability of Primary Care Services
"insurance_accepted", -- Types of Insurance Accepted
"site_name", -- Facility Name
"sliding_scale_fees", -- Availability of Sliding-Scale Fees
"accepts_uninsured_patients", -- Availability of Services for Uninsured Patients
"police_districts_served", -- Police Districts Served by Site
"wards_served", -- Aldermanic Wards Served by Site
"harm_reduction_services", -- Types of Harm Reduction Services Offered
"grief_services_availability", -- Availability of Grief/Bereavement Services
"first_episode_psychosis_programming_availability", -- Availability of First Episode Psychosis Programming
"service_request_alternative_detail", -- Alternative Means to Request Services - Detail
"grief_bereavement_services_types", -- Types of Grief/Bereavement Services
"service_request_alternative_availability", -- Alternative Means to Request Services - Availability
"mental_health_services_type_special_needs_detail", -- Types of Mental Health Services Available for Special-Needs Populations
"mar_medications_opioid", -- Types of Medication Administered for Medication-Assisted Recovery-Opioid
"mar_medications_alcohol", -- Types of Medication Administered for Medication-Assisted Recovery-Alcohol
"mental_health_services_type_special_needs_availability", -- Availability of Mental Health Services for Special-Needs Populations
"zip", -- Facility ZIP Code
"school_based_services_availability", -- Availability of School-based Services
"substance_use_services_availability", -- Availability of Substance Use Services
"substance_use_services_type", -- Types of Substance Use Services Offered
"main_phone", -- Primary Facility Phone #
"crisis_services_hours", -- Hours for Crisis Services
"evening_hours_detail", -- Detail of evening hours
"weekend_hours_availability", -- Availability of Weekend Services
"weekend_hours_detail", -- Detail of weekend hours for facility
"ticc_site" -- Is the site a Trauma-Informed Center of Care?
FROM
"cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym:latest"."cdph_mental_health_resources_deprecated_november"
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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cityofchicago.org. When you querycityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym: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.cityofchicago.org, 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 \
"cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym" \
--handler-options '{
"domain": "data.cityofchicago.org",
"tables": {
"cdph_mental_health_resources_deprecated_november": "vcv6-95ym"
}
}'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, cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym is just another Postgres schema.