And, Or and Not Operators in GraphQL

Every GraphQL search filter can use and, or, and not operators.

GraphQL syntax uses infix notation, so: “a and b” is a, and: { b }, “a or b or c” is a, or: { b, or: c }, and “not” is a prefix (not:).

The following example queries demonstrate the use of and, or, and not operators:

Example: “Posts that do not have “GraphQL” in the title”

queryPost(filter: { not: { title: { allofterms: "GraphQL"} } } ) { ... }

Example: “Posts that have “GraphQL” or “Dgraph” in the title”

queryPost(filter: {
  title: { allofterms: "GraphQL"},
  or: { title: { allofterms: "Dgraph" } }
} ) { ... }

Example: “Posts that have “GraphQL” and “Dgraph” in the title”

queryPost(filter: {
  title: { allofterms: "GraphQL"},
  and: { title: { allofterms: "Dgraph" } }
} ) { ... }

The and operator is implicit for a single filter object, if the fields don’t overlap. For example, above the and is required because title is in both filters; whereas below, and is not required.

queryPost(filter: {
  title: { allofterms: "GraphQL" },
  datePublished: { ge: "2020-06-15" }
} ) { ... }

Example: “Posts that have “GraphQL” in the title, or have the tag “GraphQL” and mention “Dgraph” in the title”

queryPost(filter: {
  title: { allofterms: "GraphQL"},
  or: { title: { allofterms: "Dgraph" }, tags: { eq: "GraphQL" } }
} ) { ... }

The and and or filter both accept a list of filters. Per the GraphQL specification, non-list filters are coerced into a list. This provides backwards-compatibility while allowing for more complex filters.

Example: “Query for posts that have GraphQL in the title but that lack the GraphQL tag, or that have Dgraph in the title but lack the Dgraph tag”

queryPost(filter: {
  or: [
    { and: [{ title: { allofterms: "GraphQL" } }, { not: { tags: { eq: "GraphQL" } } }] }
    { and: [{ title: { allofterms: "Dgraph" } }, { not: { tags: { eq: "Dgraph" } } }] }
  ]
} ) { ... }

Nesting

Nested logic with the same and/or conjunction can be simplified into a single list.

For example, the following complex query:

queryPost(filter: {
  or: [
    { or: [ { foo: { eq: "A" } }, { bar: { eq: "B" } } ] },
    { or: [ { baz: { eq: "C" } }, { quz: { eq: "D" } } ] }
  ]
} ) { ... }

…can be simplified into the following simplified query syntax:

queryPost(filter: {
  or: [
    { foo: { eq: "A" } }, 
    { bar: { eq: "B" } },
    { baz: { eq: "C" } }, 
    { quz: { eq: "D" } }
  ]
} ) { ... }