Package com.mongodb.client.model

Class Projections

java.lang.Object
com.mongodb.client.model.Projections
public final class Projections extends Object
A factory for projections. A convenient way to use this class is to statically import all of its methods, which allows usage like: 
    collection.find().projection(fields(include("x", "y"), excludeId()))
Since:
3.0
MongoDB documentation
Projection

  • Method Details

    • computed

      public static <TExpression> Bson computed(String fieldName, TExpression expression)
      Creates a projection of a field whose value is computed from the given expression. Projection with an expression can be used in the following contexts:
      • $project aggregation pipeline stage.
      • Starting from MongoDB 4.4, it's also accepted in various find-related methods within the MongoCollection-based API where projection is supported, for example:
        • find()
        • findOneAndReplace()
        • findOneAndUpdate()
        • findOneAndDelete()
      Type Parameters:
      TExpression - the expression type
      Parameters:
      fieldName - the field name
      expression - the expression
      Returns:
      the projection
      See Also:

    • computedSearchMeta

      public static Bson computedSearchMeta(String fieldName)
      Creates a projection of a field whose value is equal to the $$SEARCH_META variable, for use with Aggregates.search(SearchOperator, SearchOptions) / Aggregates.search(SearchCollector, SearchOptions). Calling this method is equivalent to calling computed(String, Object) with "$$SEARCH_META" as the second argument.
      Parameters:
      fieldName - the field name
      Returns:
      the projection
      Since:
      4.7
      See Also:

    • include

      public static Bson include(String... fieldNames)
      Creates a projection that includes all of the given fields.
      Parameters:
      fieldNames - the field names
      Returns:
      the projection

    • include

      public static Bson include(List<String> fieldNames)
      Creates a projection that includes all of the given fields.
      Parameters:
      fieldNames - the field names
      Returns:
      the projection

    • exclude

      public static Bson exclude(String... fieldNames)
      Creates a projection that excludes all of the given fields.
      Parameters:
      fieldNames - the field names
      Returns:
      the projection

    • exclude

      public static Bson exclude(List<String> fieldNames)
      Creates a projection that excludes all of the given fields.
      Parameters:
      fieldNames - the field names
      Returns:
      the projection

    • excludeId

      public static Bson excludeId()
      Creates a projection that excludes the _id field. This suppresses the automatic inclusion of _id that is the default, even when other fields are explicitly included.
      Returns:
      the projection

    • elemMatch

      public static Bson elemMatch(String fieldName)
      Creates a projection that includes for the given field only the first element of an array that matches the query filter. This is referred to as the positional $ operator.
      Parameters:
      fieldName - the field name whose value is the array
      Returns:
      the projection
      MongoDB documentation
      Project the first matching element ($ operator)

    • elemMatch

      public static Bson elemMatch(String fieldName, Bson filter)
      Creates a projection that includes for the given field only the first element of the array value of that field that matches the given query filter.
      Parameters:
      fieldName - the field name
      filter - the filter to apply
      Returns:
      the projection
      MongoDB documentation
      elemMatch

    • meta

      public static Bson meta(String fieldName, String metaFieldName)
      Creates a $meta projection to the given field name for the given meta field name.
      Parameters:
      fieldName - the field name
      metaFieldName - the meta field name
      Returns:
      the projection
      Since:
      4.1
      See Also:
      MongoDB documentation
      reference/operator/aggregation/meta/

    • metaTextScore

      public static Bson metaTextScore(String fieldName)
      Creates a projection to the given field name of the textScore, for use with text queries. Calling this method is equivalent to calling meta(String, String) with "textScore" as the second argument.
      Parameters:
      fieldName - the field name
      Returns:
      the projection
      See Also:
      MongoDB documentation
      textScore

    • metaSearchScore

      public static Bson metaSearchScore(String fieldName)
      Creates a projection to the given field name of the searchScore, for use with Aggregates.search(SearchOperator, SearchOptions) / Aggregates.search(SearchCollector, SearchOptions). Calling this method is equivalent to calling meta(String, String) with "searchScore" as the second argument.
      Parameters:
      fieldName - the field name
      Returns:
      the projection
      Since:
      4.7
      MongoDB Atlas documentation
      Scoring

    • metaVectorSearchScore

      @Beta(SERVER) public static Bson metaVectorSearchScore(String fieldName)
      Creates a projection to the given field name of the vectorSearchScore, for use with Aggregates.vectorSearch(FieldSearchPath, Iterable, String, long, long, VectorSearchOptions). Calling this method is equivalent to calling meta(String, String) with "vectorSearchScore" as the second argument.
      Parameters:
      fieldName - the field name
      Returns:
      the projection
      Since:
      4.11
      MongoDB Atlas documentation
      Scoring
      Since server release
      6.0.10

    • metaSearchHighlights

      public static Bson metaSearchHighlights(String fieldName)
      Creates a projection to the given field name of the searchHighlights, for use with Aggregates.search(SearchOperator, SearchOptions) / Aggregates.search(SearchCollector, SearchOptions). Calling this method is equivalent to calling meta(String, String) with "searchHighlights" as the second argument.
      Parameters:
      fieldName - the field name
      Returns:
      the projection
      Since:
      4.7
      See Also:
      MongoDB Atlas documentation
      Highlighting

    • slice

      public static Bson slice(String fieldName, int limit)
      Creates a projection to the given field name of a slice of the array value of that field.
      Parameters:
      fieldName - the field name
      limit - the number of elements to project.
      Returns:
      the projection
      MongoDB documentation
      Slice

    • slice

      public static Bson slice(String fieldName, int skip, int limit)
      Creates a projection to the given field name of a slice of the array value of that field.
      Parameters:
      fieldName - the field name
      skip - the number of elements to skip before applying the limit
      limit - the number of elements to project
      Returns:
      the projection
      MongoDB documentation
      Slice

    • fields

      public static Bson fields(Bson... projections)
      Creates a projection that combines the list of projections into a single one. If there are duplicate keys, the last one takes precedence.
      Parameters:
      projections - the list of projections to combine
      Returns:
      the combined projection

    • fields

      public static Bson fields(List<? extends Bson> projections)
      Creates a projection that combines the list of projections into a single one. If there are duplicate keys, the last one takes precedence.
      Parameters:
      projections - the list of projections to combine
      Returns:
      the combined projection