public class QueryImpl<T> extends SimpleQueryImpl<T> implements Query<T>, Cloneable
loader| Modifier and Type | Method and Description |
|---|---|
QueryImpl<T> |
clone() |
int |
count()
Count the total number of values in the result.
|
QueryImpl<T> |
filter(String condition,
Object value)
Create a filter based on the specified condition and value, using
the same syntax as the GAE/Python query class.
|
LoadResult<T> |
first()
Gets the first entity in the result set.
|
com.google.appengine.api.datastore.QueryResultIterable<T> |
iterable()
Starts an asynchronous query which will return entities.
|
com.google.appengine.api.datastore.QueryResultIterator<T> |
iterator() |
com.google.appengine.api.datastore.QueryResultIterable<Key<T>> |
keysIterable()
Get an iterator over the keys.
|
List<T> |
list()
Execute the query and get the results as a List.
|
QueryImpl<T> |
order(String condition)
Sorts based on a property.
|
String |
toString()
Generates a string that consistently and uniquely specifies this query.
|
protected com.google.appengine.api.datastore.Query.FilterOperator |
translate(String operator)
Converts the textual operator (">", "<=", etc) into a FilterOperator.
|
ancestor, chunk, chunkAll, distinct, endAt, filterKey, filterKey, hybrid, keys, limit, offset, reverse, startAtequals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitancestor, chunk, chunkAll, endAt, filterKey, hybrid, limit, offset, reverse, startAtdistinct, filterKey, keyspublic QueryImpl<T> filter(String condition, Object value)
QueryCreate a filter based on the specified condition and value, using the same syntax as the GAE/Python query class. Examples:
filter("age >=", age)filter("age =", age)filter("age", age) (if no operator, = is assumed)filter("age !=", age)filter("age in", ageList)The space between the property name and the operator is required.
Filtering a condition of "age>=" will perform an equality test on an entity
property exactly named "age>=". You can't create properties like this with Objectify, but you
can with the Low-Level API.
See the Google documentation for indexes for an explanation of what you can and cannot filter for.
In addition to filtering on indexed properties, you can filter on @Id properties
if this query is restricted to a ClassfilterKey() which builds the key for you.
You can not filter on @Parent properties. Use
filterKey() or ancestor() instead.
public QueryImpl<T> order(String condition)
QuerySorts based on a property. Examples:
order("age")order("-age") (descending sort)You can sort on @Id properties if this query is
restricted to a Class
You can not sort on @Parent properties.
protected com.google.appengine.api.datastore.Query.FilterOperator translate(String operator)
public String toString()
SimpleQueryGenerates a string that consistently and uniquely specifies this query. There is no way to convert this string back into a query and there is no guarantee that the string will be consistent across versions of Objectify.
In particular, this value is useful as a key for a simple memcache query cache.
toString in interface QueryExecute<T>toString in interface SimpleQuery<T>toString in class Objectpublic LoadResult<T> first()
QueryExecutefirst in interface QueryExecute<T>public int count()
SimpleQueryCount the total number of values in the result. limit and offset are obeyed. This is somewhat faster than fetching, but the time still grows with the number of results. The datastore actually walks through the result set and counts for you.
Immediately executes the query; there is no async version of this method.
WARNING: Each counted entity is billed as a "datastore minor operation". Counting large numbers of entities can quickly create massive bills.
count in interface SimpleQuery<T>public com.google.appengine.api.datastore.QueryResultIterable<T> iterable()
QueryExecuteStarts an asynchronous query which will return entities.
Note that since the Query
iterable in interface QueryExecute<T>public com.google.appengine.api.datastore.QueryResultIterator<T> iterator()
public List<T> list()
QueryExecuteExecute the query and get the results as a List. The list will be equivalent to a simple ArrayList; you can iterate through it multiple times without incurring additional datastore cost.
Note that you must be careful about limit()ing the size of the list returned; you can easily exceed the practical memory limits of Appengine by querying for a very large dataset.
list in interface QueryExecute<T>public com.google.appengine.api.datastore.QueryResultIterable<Key<T>> keysIterable()
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