com.holonplatform.datastore.mongo.core.expression

Interface BsonProjection<R>

Type Parameters:

R - Projection result type

All Superinterfaces:

com.holonplatform.core.Expression, com.holonplatform.core.TypedExpression<R>

public interface BsonProjection<R>
extends com.holonplatform.core.TypedExpression<R>

Mongo query projection expression.

Since:

5.2.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	BsonProjection.Builder<R> Builder.

Nested classes/interfaces inherited from interface com.holonplatform.core.Expression

com.holonplatform.core.Expression.ExpressionResolverFunction<E extends com.holonplatform.core.Expression,R extends com.holonplatform.core.Expression>, com.holonplatform.core.Expression.InvalidExpressionException

Method Summary

Modifier and Type	Method and Description
static <R> BsonProjection.Builder<R>	builder(Class<R> projectionType) Get a new BsonProjection builder.
static <R> BsonProjection.Builder<R>	builder(Class<R> projectionType, boolean countAllProjection) Get a new BsonProjection builder.
static BsonProjection<Long>	countAll() Create a new count all BsonProjection.
Optional<DocumentConverter<R>>	getConverter() Get the projection DocumentConverter.
List<String>	getFieldNames() Get the field names.
List<org.bson.conversions.Bson>	getFieldProjections() Get the field projection values.
Map<String,org.bson.conversions.Bson>	getFields() Get the projection fields as field name - Bson expression map.
boolean	hasAggregationFunctions() Get whether this projection include one or more aggregation functions (for example min, man, sum, avg, count).
boolean	isCountAllProjection() Get whether this projection is a count all projection.
Optional<String>	isCountFieldProjection() Get whether this projection is a count projection on a specific field name.
default boolean	isEmpty() Get whether the projection is empty.

Methods inherited from interface com.holonplatform.core.TypedExpression

getTemporalType, getType, isCollectionExpression, isConverterExpression

Methods inherited from interface com.holonplatform.core.Expression

validate

Method Detail

isEmpty

default boolean isEmpty()

Get whether the projection is empty.

Returns:

whether the projection is empty

getFields

Map<String,org.bson.conversions.Bson> getFields()

Get the projection fields as field name - Bson expression map.

Returns:

the projection fields

getFieldNames

List<String> getFieldNames()

Get the field names.

Returns:

field names

getFieldProjections

List<org.bson.conversions.Bson> getFieldProjections()

Get the field projection values.

Returns:

field projection values

getConverter

Optional<DocumentConverter<R>> getConverter()

Get the projection DocumentConverter.

Returns:

Oprional document converter

isCountAllProjection

boolean isCountAllProjection()

Get whether this projection is a count all projection.

Returns:

Whether this projection is a count all projection

isCountFieldProjection

Optional<String> isCountFieldProjection()

Get whether this projection is a count projection on a specific field name.

Returns:

If this projection is a count projection on a specific field name, return the field name, otherwise an empty Optional

hasAggregationFunctions

boolean hasAggregationFunctions()

Get whether this projection include one or more aggregation functions (for example min, man, sum, avg, count).

Returns:

Whether this projection include one or more aggregation functions

countAll

static BsonProjection<Long> countAll()

Create a new count all BsonProjection.

Returns:

A new count all BsonProjection

builder

static <R> BsonProjection.Builder<R> builder(Class<R> projectionType)

Get a new BsonProjection builder.

Type Parameters:

R - Projection result type

Parameters:

projectionType - Projection result type

Returns:

A new BsonProjection builder

builder

static <R> BsonProjection.Builder<R> builder(Class<R> projectionType,
                                             boolean countAllProjection)

Get a new BsonProjection builder.

Type Parameters:

R - Projection result type

Parameters:

projectionType - Projection result type

countAllProjection - Whether the projection is a count all projection

Returns:

A new BsonProjection builder