com.google.cloud.datastore

Class StructuredQuery<V>

java.lang.Object

com.google.cloud.datastore.Query<V>

com.google.cloud.datastore.StructuredQuery<V>

Type Parameters:

V - the type of the result values this query will produce

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

EntityQuery, KeyQuery, ProjectionEntityQuery

public abstract class StructuredQuery<V>
extends Query<V>

An implementation of a Google Cloud Datastore Query that can be constructed by providing all the specific query elements.

A usage example:

A simple query that returns all entities for a specific kind

 Query<Entity> query = Query.entityQueryBuilder().kind(kind).build();
 QueryResults<Entity> results = datastore.run(query);
 while (results.hasNext()) {
   Entity entity = results.next();
   ...
 }
 

A simple key-only query of all entities for a specific kind

 Query<Key> keyOnlyQuery =  Query.keyQueryBuilder().kind(KIND1).build();
 QueryResults<Key> results = datastore.run(keyOnlyQuery);
 ...
 

A less trivial example of a projection query that returns the first 10 results of "age" and "name" properties (sorted and grouped by "age") with an age greater than 18

 Query<ProjectionEntity> query = Query.projectionEntityQueryBuilder()
     .kind(kind)
     .projection(Projection.property("age"), Projection.first("name"))
     .filter(PropertyFilter.gt("age", 18))
     .groupBy("age")
     .orderBy(OrderBy.asc("age"))
     .limit(10)
     .build();
 QueryResults<ProjectionEntity> results = datastore.run(query);
 ...
 

See Also:

Datastore queries, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	StructuredQuery.Builder<V> Interface for StructuredQuery builders.
static class	StructuredQuery.CompositeFilter A class representing a filter composed of a combination of other filters.
static class	StructuredQuery.Filter
static class	StructuredQuery.OrderBy
static class	StructuredQuery.PropertyFilter A class representing a filter based on a single property or ancestor.

Nested classes/interfaces inherited from class com.google.cloud.datastore.Query

Query.ResultType<V>

Method Summary

Methods

Modifier and Type	Method and Description
List<String>	distinctOn()
Cursor	endCursor()
boolean	equals(Object obj)
StructuredQuery.Filter	filter()
int	hashCode()
String	kind()
Integer	limit()
int	offset()
com.google.common.collect.ImmutableList<StructuredQuery.OrderBy>	orderBy()
List<String>	projection()
Cursor	startCursor()
abstract StructuredQuery.Builder<V>	toBuilder()
String	toString()

Methods inherited from class com.google.cloud.datastore.Query

entityQueryBuilder, gqlQueryBuilder, gqlQueryBuilder, keyQueryBuilder, namespace, projectionEntityQueryBuilder

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

kind

public String kind()

projection

public List<String> projection()

filter

public StructuredQuery.Filter filter()

distinctOn

public List<String> distinctOn()

orderBy

public com.google.common.collect.ImmutableList<StructuredQuery.OrderBy> orderBy()

startCursor

public Cursor startCursor()

endCursor

public Cursor endCursor()

offset

public int offset()

limit

public Integer limit()

toBuilder

public abstract StructuredQuery.Builder<V> toBuilder()