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 directorio_instituciones_educativas_del_municipio
table in this repository, by referencing it like:
"datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w:latest"."directorio_instituciones_educativas_del_municipio"
or in a full query, like:
SELECT
":id", -- Socrata column ID
"idnit", -- Número de identificación tributaria de la Institución Educativa / Tax identification number of the Educational Institution.
"idnombremunicipio", -- Nombre del Municipio/ Name of the Municipality
"idcodigoestablecimiento", -- Código DANE asignado a la Institución Educativa/ DANE code assigned to the Educational Institution
"idnombreestablecimiento", -- Nombre de la Institución Educativa / Name of Educational Institution
"georeferenciaci_n_georeferencing", -- Ubicación definida latitud y longitud en donde está ubicada la institución o sede educativa / Location defined latitude and longitude where the institution or educational venue is located
"idnombresede", -- Nombre de la sede o institución educativa./ Name of the seat or educational institution
"iddireccion", -- Dirección física de la Institución o sede educativa / Physical address of the Institution or educational headquarters.
"idzona", -- Zona en donde esta ubicado la Institución o sede educativa / Area where the institution or educational headquarters is located
"idtelefono", -- Teléfono de contacto de la Institución o sede educativa / Contact telephone number of the Institution
"idniveles", -- Niveles educativos de la Institución o sede educativa / Educational levels of the Institution or educational headquarters
"idjornadas", -- Jornadas que maneja la Institución o sede educativa/ Conference held by the Institution or educational headquarters
"idespecialidad", -- Especialidad académica del bachillerato de Institución o sede Educativa /Academic specialty of the baccalaureate of Institution or educational headquarters
"idmatricula", -- Número de estudiantes matriculados reportados en el sistema de información de matricula SIMAT/ Number of enrolled students reported in the SIMAT enrollment information system
"idcedula", -- Documento de Identidad del Rector de la Institución educativa / Identity document of the Rector of the educational institution.
"idgrados", -- Grados que maneja la Institución o sede educativa / Grades managed by the Institution or educational headquarters
"idreconocimientooficialactualizado", -- Documento público del nombramiento del rector de la institución educativa / Public document of the appointment of the rector of the educational institution
"celular", -- Número de celular de contacto de la institución educativa o sede / Contact phone number of the educational institution.
"idcorreo", -- Correo electrónico de la Institución o sede educativa / E-mail of the Institution or educational headquarters
"idrector", -- Nombre completo del Rector de la Institución educativa/ Full name of the Rector of the educational institution.
"idmodelo", -- Modelo Educativo asignado a la Institución o sede educativa / Educational Model assigned to the Educational Institution
"tel_fono_2", -- Teléfono de contacto de la Institución o sede educativa / Contact telephone number of the Institution
"georeferenciaci_n_georeferencing_zip",
"georeferenciaci_n_georeferencing_city",
"georeferenciaci_n_georeferencing_state",
"georeferenciaci_n_georeferencing_address",
"idmucipio" -- Código Dane asignado al Municipio / Dane code assigned to the Municipality
FROM
"datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w:latest"."directorio_instituciones_educativas_del_municipio"
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 datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w
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; sgr
can 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 clone
and sgr checkout
.
Cloning Data
Because datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w: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 datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w
Checkout 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 datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w:latest
This will download all the objects for the latest
tag of datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w
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 datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w: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 datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w:latest
This 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, datos-gov-co/directorio-instituciones-educativas-del-municipio-fmaq-a76w
is just another Postgres schema.