SimpleQueryImpl (Objectify App Engine 5.0.1 API)

java.lang.Object
- com.googlecode.objectify.impl.SimpleQueryImpl<T>

All Implemented Interfaces:

com.google.appengine.api.datastore.QueryResultIterable<T>, QueryExecute<T>, SimpleQuery<T>, Iterable<T>

Direct Known Subclasses:

LoaderImpl, QueryImpl
```
public abstract class SimpleQueryImpl<T>
extends Object
implements SimpleQuery<T>
```
Base for command classes that include methods for defining a query (filter, order, limit, etc). Does not include the methods for executing a query.

Author:

Jeff Schnitzer

Field Summary

Fields
Modifier and Type Field and Description

protected LoaderImpl<?> loader

Fields
Modifier and Type	Field and Description
`protected LoaderImpl<?>`	`loader`

Method Summary

Methods
Modifier and Type	Method and Description
`QueryImpl<T>`	`ancestor(Object keyOrEntity)` Restricts result set only to objects which have the given ancestor somewhere in the chain.
`QueryImpl<T>`	`chunk(int value)` Sets the internal chunking and prefetching strategy within the low-level API.
`QueryImpl<T>`	`chunkAll()` Sets the internal chunking and prefetching strategy within the low-level API to attempt to get all results at once.
`QueryImpl<T>`	`distinct(boolean value)` Determines whether this is a SELECT DISTINCT query.
`QueryImpl<T>`	`endAt(com.google.appengine.api.datastore.Cursor value)` Ends query results at the specified Cursor.
`QueryImpl<T>`	`filterKey(Object value)` An alias for `filterKey("=", value)`
`QueryImpl<T>`	`filterKey(String condition, Object value)` Create a filter on the key of an entity.
`QueryImpl<T>`	`hybrid(boolean force)` This method forces Objectify to (or not to) hybridize the query into a keys-only fetch plus batch get.
`QueryKeys<T>`	`keys()` Switches to a keys-only query.
`QueryImpl<T>`	`limit(int value)` Limit the fetched result set to a certain number of values.
`QueryImpl<T>`	`offset(int value)` Starts the query results at a particular zero-based offset.
`QueryImpl<T>`	`orderKey(boolean descending)` Orders results by the key.
`QueryImpl<T>`	`reverse()` Reverse the query, as described in the GAE docs.
`QueryImpl<T>`	`startAt(com.google.appengine.api.datastore.Cursor value)` Starts query results at the specified Cursor.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.googlecode.objectify.cmd.SimpleQuery
count, toString

Methods inherited from interface com.googlecode.objectify.cmd.QueryExecute
first, iterable, list

Methods inherited from interface com.google.appengine.api.datastore.QueryResultIterable
iterator

- Field Detail
  - loader
```
protected LoaderImpl<?> loader
```
- Method Detail
  - filterKey
```
public QueryImpl<T> filterKey(String condition,
                     Object value)
```
    Description copied from interface: SimpleQuery
    Create a filter on the key of an entity. Examples:
    - filterKey(">=", key) (standard inequalities)
    - filterKey("=", key) (wouldn't you rather do a load-by-key?)
    - filterKey("", key) (if no operator, = is assumed)
    - filterKey("!=", key)
    - filterKey("in", keyList) (wouldn't you rather do a batch load-by-key?)
    The key parameter can be anything key-ish; a Key, a native datastore key, a Ref, a pojo entity, etc.
    
    See the Google documentation for indexes for an explanation of what you can and cannot filter for.
    Specified by:
    
    filterKey in interface SimpleQuery<T>
  - filterKey
```
public QueryImpl<T> filterKey(Object value)
```
    Description copied from interface: SimpleQuery
    
    An alias for filterKey("=", value)
    
    Specified by:
    
    filterKey in interface SimpleQuery<T>
  - orderKey
```
public QueryImpl<T> orderKey(boolean descending)
```
    Description copied from interface: SimpleQuery
    
    Orders results by the key.
    
    Specified by:
    
    orderKey in interface SimpleQuery<T>
    
    Parameters:
    descending - if true, specifies a descending (aka reverse) sort
  - ancestor
```
public QueryImpl<T> ancestor(Object keyOrEntity)
```
    Description copied from interface: SimpleQuery
    
    Restricts result set only to objects which have the given ancestor somewhere in the chain. Doesn't need to be the immediate parent. The specified ancestor itself will be included in the result set (if it exists).
    
    Specified by:
    
    ancestor in interface SimpleQuery<T>
    
    Parameters:
    keyOrEntity - can be a Key, a Key, or an Objectify entity object.
  - limit
```
public QueryImpl<T> limit(int value)
```
    Description copied from interface: SimpleQuery
    
    Limit the fetched result set to a certain number of values.
    
    Specified by:
    
    limit in interface SimpleQuery<T>
    
    Parameters:
    value - must be >= 0. A value of 0 indicates no limit.
  - offset
```
public QueryImpl<T> offset(int value)
```
    Description copied from interface: SimpleQuery
    
    Starts the query results at a particular zero-based offset. This can be extraordinarily expensive because each skipped entity is billed as a "minor datastore operation". If you can, you probably want to use cursors instead.
    
    Specified by:
    
    offset in interface SimpleQuery<T>
    
    Parameters:
    value - must be >= 0
  - startAt
```
public QueryImpl<T> startAt(com.google.appengine.api.datastore.Cursor value)
```
    Description copied from interface: SimpleQuery
    
    Starts query results at the specified Cursor. You can obtain a Cursor from a QueryResultIterator by calling the getCursor() method. Note that limit() and offset() are NOT encoded within a cursor; they operate on the results of the query after a cursor is established.
    
    Specified by:
    
    startAt in interface SimpleQuery<T>
  - endAt
```
public QueryImpl<T> endAt(com.google.appengine.api.datastore.Cursor value)
```
    Description copied from interface: SimpleQuery
    
    Ends query results at the specified Cursor. You can obtain a Cursor from a QueryResultIterator by calling the getCursor() method. Note that limit() and offset() are NOT encoded within a cursor; they operate on the results of the query after a cursor is established.
    
    Specified by:
    
    endAt in interface SimpleQuery<T>
  - chunk
```
public QueryImpl<T> chunk(int value)
```
    Description copied from interface: SimpleQuery
    
    Sets the internal chunking and prefetching strategy within the low-level API. Affects performance only; the result set will be the same.
    
    Specified by:
    
    chunk in interface SimpleQuery<T>
    
    Parameters:
    value - must be >= 0
  - distinct
```
public QueryImpl<T> distinct(boolean value)
```
    Description copied from interface: SimpleQuery
    
    Determines whether this is a SELECT DISTINCT query.
    
    Specified by:
    
    distinct in interface SimpleQuery<T>
  - hybrid
```
public QueryImpl<T> hybrid(boolean force)
```
    Description copied from interface: SimpleQuery
    This method forces Objectify to (or not to) hybridize the query into a keys-only fetch plus batch get.
    
    If Objectify knows you are fetching an entity type that can be cached, it automatically converts queries into a "hybrid" of keys-only query followed by a batch fetch of the keys. This is cheaper (keys-only results are 1/7th the price of a full fetch) and, if the cache hits, significantly faster. However, there are some circumstances in which you may wish to force behavior one way or another:
    - Issuing a kindless query (which Objectify will not auto-hybridize) when you know a significant portion of the result set is cacheable.
    - Some exotic queries cannot be made keys-only, and produce an exception from the Low-Level API when you try to execute the query. Objectify tries to detect these cases but since the underlying implementation may change, you may need to force hybridization off in some cases.
    - Hybrid queries have a slightly different consistency model than normal queries. You may wish to force hybridization off to ensure a weakly consistent query (see below).
    For the most part, hybridization only affects the performance and cost of queries. However, it is possible for hybridization to alter the content of the result set. In the HRD, queries always have EVENTUAL consistency but get operations may have either STRONG or EVENTUAL consistency depending on the read policy (see Objectify.consistency(). The keys-only query results will always be EVENTUAL and may return data that has been deleted, but Objectify will exclude these results when the more-current batch get fails to return data. So the count of the returned data may actually be less than the limit(), even if there are plenty of actual results. hybrid(false) will prevent this behavior.
    
    Note that in hybrid queries, the chunk size defines the batch size.
    Specified by:
    
    hybrid in interface SimpleQuery<T>
  - chunkAll
```
public QueryImpl<T> chunkAll()
```
    Description copied from interface: SimpleQuery
    
    Sets the internal chunking and prefetching strategy within the low-level API to attempt to get all results at once. Affects performance only; the result set will be the same.
    
    Same as chunk(Integer.MAX_VALUE).
    
    Specified by:
    
    chunkAll in interface SimpleQuery<T>
  - keys
```
public QueryKeys<T> keys()
```
    Description copied from interface: SimpleQuery
    
    Switches to a keys-only query. Keys-only responses are billed as "minor datastore operations" which are significantly cheaper (~7X) than fetching whole entities.
    
    Specified by:
    
    keys in interface SimpleQuery<T>
  - reverse
```
public QueryImpl<T> reverse()
```
    Description copied from interface: SimpleQuery
    
    Reverse the query, as described in the GAE docs.
    
    Specified by:
    
    reverse in interface SimpleQuery<T>

Class SimpleQueryImpl<T>

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.googlecode.objectify.cmd.SimpleQuery

Methods inherited from interface com.googlecode.objectify.cmd.QueryExecute

Methods inherited from interface com.google.appengine.api.datastore.QueryResultIterable

Field Detail

loader

Method Detail

filterKey

filterKey

orderKey

ancestor

limit

offset

startAt

endAt

chunk

distinct

hybrid

chunkAll

keys

reverse