v1.2.0

Added

• Extended JSON fields now support all comparison and aggregation functions (#99)
• Update to ndc-spec v0.1.6 which allows filtering by object values in array fields (#101)

Filtering by values in arrays

In this update you can filter by making comparisons to object values inside
arrays. For example consider a MongoDB database with these three documents:

{ "institution": "Black Mesa", "staff": [{ "name": "Freeman" }, { "name": "Calhoun" }] }
{ "institution": "Aperture Science", "staff": [{ "name": "GLaDOS" }, { "name": "Chell" }] }
{ "institution": "City 17", "staff": [{ "name": "Alyx" }, { "name": "Freeman" }, { "name": "Breen" }] }

You can now write a GraphQL query with a where clause that checks individual
entries in the staff arrays:

query {
  institutions(where: { staff: { name: { _eq: "Freeman" } } }) {
    institution
  }
}

Which produces the result:

{ "data": { "institutions": [
  { "institution": "Black Mesa" },
  { "institution": "City 17" } 
] } }

The filter selects documents where any element in the array passes the
condition. If you want to select only documents where every array element
passes then negate the comparison on array element values, and also negate the
entire predicate like this:

query EveryElementMustMatch {
  institutions(
    where: { _not: { staff: { name: { _neq: "Freeman" } } } }
  ) {
    institution
  }
}

Note: It is currently only possible to filter on arrays that contain
objects. Filtering on arrays that contain scalar values or nested arrays will
come later.

To configure DDN metadata to filter on array fields configure the
BooleanExpressionType for the containing document object type to use an
object boolean expression type for comparisons on the array field. The
GraphQL Engine will transparently distribute object comparisons over array
elements. For example the above example is configured with this boolean
expression type for documents:

---
kind: BooleanExpressionType
version: v1
definition:
  name: InstitutionComparisonExp
  operand:
    object:
      type: Institution
      comparableFields:
        - fieldName: id
          booleanExpressionType: ObjectIdComparisonExp
        - fieldName: institution
          booleanExpressionType: StringComparisonExp
        - fieldName: staff
          booleanExpressionType: InstitutionStaffComparisonExp
      comparableRelationships: []
  logicalOperators:
    enable: true
  isNull:
    enable: true
  graphql:
    typeName: InstitutionComparisonExp

InstitutionStaffComparisonExp is the boolean expression type for objects
inside the staff array. It looks like this:

---
kind: BooleanExpressionType
version: v1
definition:
  name: InstitutionStaffComparisonExp
  operand:
    object:
      type: InstitutionStaff
      comparableFields:
        - fieldName: name
          booleanExpressionType: StringComparisonExp
      comparableRelationships: []
  logicalOperators:
    enable: true
  isNull:
    enable: true
  graphql:
    typeName: InstitutionStaffComparisonExp

Fixed

Changed