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org.apache.gora.query
Interface Query<K,T extends Persistent>

All Superinterfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.io.Writable

All Known Subinterfaces:

PartitionQuery<K,T>

All Known Implementing Classes:

AccumuloQuery, AvroQuery, CassandraQuery, FileSplitPartitionQuery, HBaseQuery, MemStore.MemQuery, PartitionQueryImpl, QueryBase, SqlQuery

public interface Query<K,T extends Persistent>
extends org.apache.hadoop.io.Writable, org.apache.hadoop.conf.Configurable

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

Method Summary

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()
K	getKey()
long	getLimit() Returns the maximum number of results
K	getStartKey()
long	getStartTime()
long	getTimestamp()
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	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	setStartKey(K startKey)
void	setStartTime(long startTime)
void	setTimeRange(long startTime, long endTime)
void	setTimestamp(long timestamp)

Methods inherited from interface org.apache.hadoop.io.Writable

readFields, write

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

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()
                                       throws IOException

Executes the Query on the DataStore and returns the results.

Returns:

the Result for the query.

Throws:

IOException

setFields

void setFields(String... fieldNames)

getFields

String[] getFields()

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