org.apache.gora.query

Interface Query<K,T extends Persistent>

All Known Subinterfaces:

PartitionQuery<K,T>

All Known Implementing Classes:

AccumuloQuery, AvroQuery, CassandraQuery, FileSplitPartitionQuery, HBaseQuery, MemStore.MemQuery, MongoDBQuery, PartitionQueryImpl, PartitionWSQueryImpl, QueryBase, QueryWSBase, SolrQuery

public interface Query<K,T extends Persistent>

A query to a data store to retrieve objects. Queries are constructed by the DataStore implementation via DataStore.newQuery().

Method Summary

Methods

Modifier and Type	Method and Description
Result<K,T>	execute() Executes the Query on the DataStore and returns the results.
DataStore<K,T>	getDataStore() Returns the DataStore, that this Query is associated with.
K	getEndKey()
long	getEndTime()
String[]	getFields()
Filter<K,T>	getFilter()
K	getKey()
long	getLimit() Returns the maximum number of results
K	getStartKey()
long	getStartTime()
long	getTimestamp()
boolean	isLocalFilterEnabled()
void	setDataStore(DataStore<K,T> dataStore) Sets the dataStore of this query.
void	setEndKey(K endKey)
void	setEndTime(long endTime)
void	setFields(String... fieldNames)
void	setFilter(Filter<K,T> filter)
void	setKey(K key)
void	setKeyRange(K startKey, K endKey) Set the range of keys over which the query will execute.
void	setLimit(long limit) Sets the maximum number of results to return.
void	setLocalFilterEnabled(boolean enable) Set whether the local filter is enabled.
void	setStartKey(K startKey)
void	setStartTime(long startTime)
void	setTimeRange(long startTime, long endTime)
void	setTimestamp(long timestamp)

Method Detail

setDataStore

void setDataStore(DataStore<K,T> dataStore)

Sets the dataStore of this query. Under normal operation, this call is not necessary and it is potentially dangerous. So use this method only if you know what you are doing.

Parameters:

dataStore - the dataStore of the query

getDataStore

DataStore<K,T> getDataStore()

Returns the DataStore, that this Query is associated with.

Returns:

the DataStore of the Query

execute

Result<K,T> execute()

Executes the Query on the DataStore and returns the results.

Returns:

the Result for the query.

setFields

void setFields(String... fieldNames)

getFields

String[] getFields()

setFilter

void setFilter(Filter<K,T> filter)

Parameters:

Set - a filter on this query.

getFilter

Filter<K,T> getFilter()

Returns:

The filter on this query, or null if none.

setLocalFilterEnabled

void setLocalFilterEnabled(boolean enable)

Set whether the local filter is enabled. This is usually called by data store implementations that install the filter remotely (for efficiency reasons) and therefore disable the local filter.

Parameters:

enable -

isLocalFilterEnabled

boolean isLocalFilterEnabled()

Returns:

Whether the local filter is enabled. See setLocalFilterEnabled(boolean).

setKey

void setKey(K key)

setStartKey

void setStartKey(K startKey)

Parameters:

startKey - an inclusive start key

setEndKey

void setEndKey(K endKey)

Parameters:

endKey - an inclusive end key

setKeyRange

void setKeyRange(K startKey,
               K endKey)

Set the range of keys over which the query will execute.

Parameters:

startKey - an inclusive start key

endKey - an inclusive end key

getKey

K getKey()

getStartKey

K getStartKey()

getEndKey

K getEndKey()

setTimestamp

void setTimestamp(long timestamp)

setStartTime

void setStartTime(long startTime)

setEndTime

void setEndTime(long endTime)

setTimeRange

void setTimeRange(long startTime,
                long endTime)

getTimestamp

long getTimestamp()

getStartTime

long getStartTime()

getEndTime

long getEndTime()

setLimit

void setLimit(long limit)

Sets the maximum number of results to return.

getLimit

long getLimit()

Returns the maximum number of results

Returns:

the limit if it is set, otherwise a negative number