Queries

The full query DSL of Elasticsearch is exposed through the search method. For example, if you wanted to find all people between ages 21 and 30:

const people = await Person.search({
  range: {
    age:{
      from:21,
      to: 30
    }
  }
});

See the Elasticsearch Query DSL docs for more information.

You can also specify query options like sorts

const sortedPeople = await Person.search({/* ... */}, { sort: "age:asc" });

And also aggregations:

const results = await Person.search({/* ... */}, {
  aggs: {
    'names': {
      'terms': {
        'field': 'name'
      }
    }
  }
});

Options for queries must adhere to the javascript elasticsearch driver specs.

Raw queries

A full ElasticSearch query object can be provided to mongoosastic through .esSearch() method. It can be useful when paging results. The query to be provided wraps the query object provided to .search() method and accepts the same options:

var rawQuery = {
    from: 60,
    size: 20,
    query: /* query object as in .search() */
};

await Model.esSearch(rawQuery, options);

For example:

// only the 61st to 80th ranked people who fit the age group are here!
const people = await Person.esSearch({
  from: 60,
  size: 20,
  query: {
    range: {
      age:{
        from:21,
        to: 30
      }
    }
  }
});

Hydration

By default objects returned from performing a search will be the objects as is in Elasticsearch. This is useful in cases where only what was indexed needs to be displayed (think a list of results) while the actual mongoose object contains the full data when viewing one of the results.

However, if you want the results to be actual mongoose objects you can provide { hydrate: true } as the second argument to a search call.

The hydrated results will be accessible through .hydrated property.

const results = await User.search(
  {
    query_string: {
      query: 'john'
    }
  },
  { hydrate: true }
);

console.log(results.body.hits.hits) // will be empty: []
console.log(results.body.hits.hydrated)

You can also pass in a hydrateOptions object with information on how to query for the mongoose object.

const results = await User.search(
  {
    query_string: {
      query: 'john'
    }
  },
  {
    hydrate: true,
    hydrateOptions: { select: 'name age' }
  },
);

Original ElasticSearch result data can be kept with hydrateWithESResults option. Documents are then enhanced with a _esResult property

const results = await User.search(
  {
    query_string: {
      query: 'john'
    }
  },
  {
    hydrate: true,
    hydrateWithESResults: true,
    hydrateOptions: { select: 'name age' }
  }
);

results.body.hits.hydrated.forEach(function(result) {
  console.log(
    'score',
    result._id,
    result._esResult._score
  );
});

By default the _esResult._source document is skipped. It can be added with the option hydrateWithESResults: { source: false }.

You can also default this to always be the case by providing it as a plugin option (as well as setting default hydrate options):

var User = new Schema({
    name: { type: String, es_indexed: true },
    email: String,
    city: String
})

User.plugin(mongoosastic, {
  alwaysHydrate: true,
  hydrateOptions: {
    lean: true
  }
})

Note using hydrate will be a degree slower as it will perform an Elasticsearch query and then do a query against mongodb for all the ids returned from the search result.