LDIO Relational Database Out

Ldio:LdioRdbOut

The LDIO RDB Out will transform the RDF model into a relational database using a SPARQL query.

Configure your database connection like you would normally do for a Spring boot application ( see Spring Boot Data Access and Spring Boot Common Application Properties for more details).

You have to create the database table beforehand. Then, you can use a SPARQL query to insert the data into that table. All variable names in the SPARQL query will be mapped to the column names of the database table.

You can set the ignore-duplicate-key-exception when you have duplicate key constraints on your table, and when you try to insert multiple times the same data. When you set this to true, the pipeline will not halt, and will proceed with the next member(s). This behavior is only working for a Postgresql database right now, but we are planning to add support for other databases in the future.

Config

Property	Description	Required	Default	Supported values	Example
table-name	The name of the database table where the data will be stored	Yes	N/A	String	sensor
sparql-select-query	A SPARQL SELECT query to format the members into a tabular format	Yes	N/A	String
ignore-duplicate-key-exception	Change the behaviour of the pipeline when you have a duplicate key constraint exception	No	false	Boolean value	true

Configuration Example

application.yaml that is mounted in the LDIO Workbench container under /ldio/application.yaml:

spring:
  datasource:
    url: "jdbc:postgresql://localhost:5432/mydatabase"
    username: "dbuser"
    password: "dbpass"
    configuration:
      maximum-pool-size: 30

pipeline:

orchestrator:
  pipelines:
    name: my-pipeline
    input:
      name: Ldio:LdesClient
      config:
        urls:
          - http://localhost:8080/my-ldes
        sourceFormat: text/turtle
    outputs:
      - name: Ldio:LdioRdbOut
        config:
          table-name: sensor
          sparql-select-query: -|
            SELECT ?sensor_id ?sensor ?latitude ?longitude ?generated_at_time ?feature_of_interest
            WHERE {
            ?sensor_id <http://purl.org/dc/terms/isVersionOf> ?sensor ;
            <http://www.w3.org/2003/01/geo/wgs84_pos#lat_Lambert72> ?latitude ;
            <http://www.w3.org/2003/01/geo/wgs84_pos#long_Lambert72> ?longitude ;
            <http://www.w3.org/ns/prov#generatedAtTime> ?generated_at_time ;
            <http://www.w3.org/ns/sosa/hasFeatureOfInterest> ?feature_of_interest .
            }
          ignore-duplicate-key-exception: true