External Foreign Keys

Authors	Stephen Gates

A foreign key is a reference where values in a field (or fields) in a Tabular Data Resource link to values in a field (or fields) in a Tabular Data Resource in the same or in another Tabular Data Package.

This pattern allows users to link values in a field (or fields) in a Tabular Data Resource to values in a field (or fields) in a Tabular Data Resource in a different Tabular Data Package.

Specification

The foreignKeys array MAY have a property package. This property MUST be, either:

• a string that is a fully qualified HTTP address to a Data Package datapackage.json file
• a data package name that can be resolved by a canonical data package registry

If the referenced data package has an id that is a fully qualified HTTP address, it SHOULD be used as the package value.

For example:

"foreignKeys": [{
    "fields": ["code"],
    "reference": {
      "package": "https://raw.githubusercontent.com/frictionlessdata/example-data-packages/master/donation-codes/datapackage.json",
      "resource": "donation-codes",
      "fields": ["donation code"]
    }
  }]