A JSON-LD Context
for the query. In an API, this will frequently be implicit. For example,
using json-rql as the body of a POST
to
http://example.com/my-api/v1/person/query
might have the implicit context
of a Person (possibly found at http://example.com/my-api/v1/person
).
Specifies a single Variable or Iri to return. Each matched value for the identified variable will be output as a Subject with its top-level properties.
The data pattern to match, as a set of subjects or a group. Variables are used as placeholders to capture matching properties and values in the domain.
Examples:
Match a subject by its @id
{
...
"@where": { "@id": "fred" }
}
Match a subject where any property has a given value
{
...
"@where": {
"@id": "?id",
"?prop": "Bedrock"
}
}
Match a subject with a given property, having any value
{
...
"@where": {
"@id": "?id",
"name": "?name"
}
}
The Javascript engine supports exact-matches for subject identities, properties and values. Inline filters will be available in future.
Generated using TypeDoc. Delivered by Vercel. @m-ld/m-ld - v0.5.0 Source code licensed MIT. Privacy policy
A simple means to get the properties of a specific subject, or a set of subjects matching some
@where
clause.Examples:
Describe a specific subject whose
@id
isfred
{ "@describe": "fred" }
Describe all subjects in the domain
{ "@describe": "?id", "@where": { "@id": "?id" } }
Describe subjects with a property
age
of40
{ "@describe": "?id", "@where": { "@id": "?id", "age": 40 } }
Describe all subjects referenced by
fred
via any property{ "@describe": "?id", "@where": { "@id": "fred", "?prop": { "@id": "?id" } } }
See the
@where
property for more examples of how to use a where clause.https://json-rql.org/interfaces/describe.html