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
"insurance_accepted", -- Types of Insurance Accepted
"service_request_alternative_detail", -- Alternative Means to Request Services - Detail
"sliding_scale_fees", -- Availability of Sliding-Scale Fees
"service_request_alternative_availability", -- Alternative Means to Request Services - Availability
"service_request_phone", -- Service Request Phone #
"weekend_hours_detail", -- Detail of weekend hours for facility
"ticc_site", -- Is the site a Trauma-Informed Center of Care?
"ticc_areas_served", -- Trauma-Informed Center of Care Service Area
"mar_medications_opioid", -- Types of Medication Administered for Medication-Assisted Recovery-Opioid
"mar_medications_alcohol", -- Types of Medication Administered for Medication-Assisted Recovery-Alcohol
"location", -- The location of the clinic in a format that allows for creation of maps and other geographic operations on this data portal.
"harm_reduction_services", -- Types of Harm Reduction Services Offered
"grief_services_availability", -- Availability of Grief/Bereavement Services
"grief_bereavement_services_types", -- Types of Grief/Bereavement Services
"first_episode_psychosis_programming_detail", -- First Episode Psychosis Programming - Detail
"first_episode_psychosis_programming_availability", -- Availability of First Episode Psychosis Programming
"site_name", -- Facility Name
":@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.
":@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_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_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_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.
"organization", -- Organization or Agency
"school_based_services_availability", -- Availability of School-based Services
"site_type", -- Type of Health Center
"address", -- Facility Address
"zip", -- Facility ZIP Code
"substance_use_services_availability", -- Availability of Substance Use Services
"substance_use_services_type", -- Types of Substance Use Services Offered
"crisis_services_hours", -- Hours for Crisis Services
"crisis_services_types", -- Types of Crisis Services Offered
"mental_health_services_type_special_needs_availability", -- Availability of Mental Health Services for Special-Needs Populations
"mental_health_services_type_special_needs_detail", -- Types of Mental Health Services Available for Special-Needs Populations
"weekend_hours_availability", -- Availability of Weekend Services
"accepts_uninsured_patients", -- Availability of Services for Uninsured Patients
"main_phone", -- Primary Facility Phone #
"evening_hours_detail", -- Detail of evening hours
"evening_hours_availability", -- Availability of Evening Services
"hours", -- Facility Hours
"crisis_intake_phone", -- Crisis Intake Phone #
"crisis_services", -- Availability of Crisis Services
"behavioral_services_types", -- Types of Behavioral Health Services Offered
"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
"all_community_areas_served", -- All Community Areas Served by Site
"wards_served", -- Aldermanic Wards Served by Site
"police_districts_served", -- Police Districts Served by Site
"bhs_service_availability_primary_care", -- Restriction of Behavioral Health Services For Primary Care Patients Only
"primary_care_availability" -- Availability of Primary Care Services
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.
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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym: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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ymCheckout 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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym:latestThis will download all the objects for the latest tag of cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym 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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym: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 cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym: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, cityofchicago/cdph-mental-health-resources-deprecated-november-vcv6-95ym is just another Postgres schema.