Filter query results

This library supports flexible type safe criteria expressions with user-friendly SQL query syntax semantics using where arguments and select field to specify the entity graph query with entiy attribute names as a combination of logical expressions like EQ, NE, GT, GE, LT, LR, IN, NIN, IS_NULL, NOT_NULL, BETWEEN, NOT_BETWEEN. You can use logical AND/OR combinations in SQL criteria expressions to specify complex criterias to fetch your data from SQL database. If you omit, where argument, all entities will be returned.

{
  Books(where: {title: {EQ: "War and Peace"}}) {
    select {
      id
      title
      tags
    }
  }
}

{
  "data": {
    "Books": {
      "select": [
        {
          "id": 2,
          "title": "War and Peace",
          "tags": [
            "piece",
            "war"
          ]
        }
      ]
    }
  }
}

Relation Attributes in Where Criteria Expressions:

It is also possible to specify complex filters using many-to-one and one-to-many entity attributes in where criteria expressions with variable parameter bindings, i.e.

Given the following query with many-to-one relation with variables {"authorId": 1 } :

query($authorId: Long) {  
  Books(where: {
    author: {id: {EQ: $authorId}}
  }) {
    select {
      id
      title
      genre
      author {
        id
        name
      }
    }
  }
}

{
  "data": {
    "Books": {
      "select": [
        {
          "id": 2,
          "title": "War and Peace",
          "genre": "NOVEL",
          "author": {
            "id": 1,
            "name": "Leo Tolstoy"
          }
        },
        {
          "id": 3,
          "title": "Anna Karenina",
          "genre": "NOVEL",
          "author": {
            "id": 1,
            "name": "Leo Tolstoy"
          }
        }
      ]
    }
  }
}

And given the following query with one-to-many relation:

query {
  Authors(where: {
    books: {genre: {IN: NOVEL}}
  }) {
    select {
      id
      name
      books {
        id
        title
        genre
      }
    }
  }
}

will result in

{
  "data": {
    "Authors": {
      "select": [
        {
          "id": 1,
          "name": "Leo Tolstoy",
          "books": [
            {
              "id": 2,
              "title": "War and Peace",
              "genre": "NOVEL"
            },
            {
              "id": 3,
              "title": "Anna Karenina",
              "genre": "NOVEL"
            }
          ]
        }
      ]
    }
  }
}

It is possible to use compound criteria in where search expressions given:

query {
  Authors(where: {
    books: {
      genre: {IN: NOVEL}
      title: {LIKE: "War"}
    }
  }) {
    select {
      id
      name
      books {
        id
        title
        genre
      }
    }
  }
}

Will return filtered inner collection result:

{
  "data": {
    "Authors": {
      "select": [
        {
          "id": 1,
          "name": "Leo Tolstoy",
          "books": [
            {
              "id": 2,
              "title": "War and Peace",
              "genre": "NOVEL"
            }
          ]
        }
      ]
    }
  }
}

It is also possible to filter inner collections as follows:

query {
  Authors(where: {
    books: {genre: {IN: NOVEL}}
  }) {
    select {
      id
      name
      books(where: {title: {LIKE: "War"}}) {
        id
        title
        genre
      }
    }
  }
}

will result in

{
  "data": {
    "Authors": {
      "select": [
        {
          "id": 1,
          "name": "Leo Tolstoy",
          "books": [
            {
              "id": 2,
              "title": "War and Peace",
              "genre": "NOVEL"
            }
          ]
        }
      ]
    }
  }
}