net.tinyos.tinydb
Class TinyDBQuery

java.lang.Object
  |
  +--net.tinyos.tinydb.TinyDBQuery

public class TinyDBQuery

extends java.lang.Object

TinyDBQuery is a Java data structure representing a query running (or to be run) on a set of motes. Queries consist of: - a list of fields to select - a list of expressions over those fields, where an expression is - an filter that rejects some readings - an aggregate that combines local readings with readings from neighbors. In addition to allowing a query to be built, this class includes methods to generate radio messages so the query can be distributed over the network or to abort the query

Field Summary

short	epochDur
byte	from_qid
static short	kEPOCH_DUR_ONE_SHOT
static byte	NO_FROM_QUERY
byte	qid

Constructor Summary

TinyDBQuery(byte qid, short epochDur)
Constructor

Method Summary

net.tinyos.message.Message	abortMessage() Return a byte array representing a radio message that will tell motes to abort this query
boolean	active()
void	addExpr(net.tinyos.tinydb.QueryExpr e) Add the specified expression to the query
void	addField(net.tinyos.tinydb.QueryField f) Add the specified field to the query
boolean	containsNonAggFields() Returns true iff the query contains a field that isn't contained in any aggregate.
java.util.Vector	getColumnHeadings()
net.tinyos.tinydb.QueryExpr	getExpr(int i)
net.tinyos.tinydb.QueryField	getField(int i) Return the ith field in this query
byte	getFieldType(int idx)
byte	getFromQid()
net.tinyos.tinydb.AggExpr	getGroupExpr()
int	getId() Return the id of the query
java.lang.String	getSQL() Return the text of the SQL for this query as set by setSQL (Note that TinyDBQuery does not include an interface for generating SQL from an arbitrary query.)
java.lang.String	groupColName() Return the name of the group by column
boolean	grouped() Return true if the query is grouped (e.g.
boolean	hasOutputAction()
boolean	isAgg() Return true if this query contains one or more aggregate expressions
java.util.Iterator	messageIterator() Return an Iterator over messages to be sent to start sensors running this query
int	numExprs()
int	numFields() Return the number of fields in this query
void	setActive(boolean active)
void	setEpoch(short epochDur)
void	setFromQid(byte qid) Set the id of the query this query reads results from
void	setGrouped(boolean isGrouped)
void	setGroupExpr(net.tinyos.tinydb.AggExpr ae)
void	setId(byte qid)
void	setOutputCommand(java.lang.String cmd)
void	setOutputCommand(java.lang.String cmd, short param)
void	setSQL(java.lang.String s) Set the SQL string associated with this query.
java.lang.String	toString()
void	useRamBuffer(short size)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

qid

public byte qid

from_qid

public byte from_qid

epochDur

public short epochDur

NO_FROM_QUERY

public static final byte NO_FROM_QUERY

See Also:

Constant Field Values

kEPOCH_DUR_ONE_SHOT

public static final short kEPOCH_DUR_ONE_SHOT

See Also:

Constant Field Values

Constructor Detail

TinyDBQuery

public TinyDBQuery(byte qid,
                   short epochDur)

Constructor

Parameters:

qid - The id of the query

epochDur - The rate at which results from the query should be generated

Method Detail

getId

public int getId()

Return the id of the query

setId

public void setId(byte qid)

setEpoch

public void setEpoch(short epochDur)

addField

public void addField(net.tinyos.tinydb.QueryField f)

Add the specified field to the query

addExpr

public void addExpr(net.tinyos.tinydb.QueryExpr e)

Add the specified expression to the query

grouped

public boolean grouped()

Return true if the query is grouped (e.g. contains one or more aggregates with a group by expression)

setGrouped

public void setGrouped(boolean isGrouped)

setGroupExpr

public void setGroupExpr(net.tinyos.tinydb.AggExpr ae)

getGroupExpr

public net.tinyos.tinydb.AggExpr getGroupExpr()

groupColName

public java.lang.String groupColName()

Return the name of the group by column

getSQL

public java.lang.String getSQL()

Return the text of the SQL for this query as set by setSQL (Note that TinyDBQuery does not include an interface for generating SQL from an arbitrary query.)

setSQL

public void setSQL(java.lang.String s)

Set the SQL string associated with this query. Note that this string doesn't not neccessarily have any relationship to the fields / expressions in this object

isAgg

public boolean isAgg()

Return true if this query contains one or more aggregate expressions

numExprs

public int numExprs()

getExpr

public net.tinyos.tinydb.QueryExpr getExpr(int i)
                                    throws java.lang.ArrayIndexOutOfBoundsException

java.lang.ArrayIndexOutOfBoundsException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

containsNonAggFields

public boolean containsNonAggFields()

Returns true iff the query contains a field that isn't contained in any aggregate. NOTE: Will return FALSE in this example "Select light, avg(light) from sensors" But, tinydb processes this query if it were "Select avg(light) from sensors"

setOutputCommand

public void setOutputCommand(java.lang.String cmd,
                             short param)

setOutputCommand

public void setOutputCommand(java.lang.String cmd)

hasOutputAction

public boolean hasOutputAction()

numFields

public int numFields()

Return the number of fields in this query

getField

public net.tinyos.tinydb.QueryField getField(int i)
                                      throws java.lang.ArrayIndexOutOfBoundsException

Return the ith field in this query

Throws:

java.lang.ArrayIndexOutOfBoundsException - if i < 0 or i >= numFields()

abortMessage

public net.tinyos.message.Message abortMessage()

Return a byte array representing a radio message that will tell motes to abort this query

getColumnHeadings

public java.util.Vector getColumnHeadings()

getFieldType

public byte getFieldType(int idx)
                  throws java.lang.ArrayIndexOutOfBoundsException

java.lang.ArrayIndexOutOfBoundsException

messageIterator

public java.util.Iterator messageIterator()

Return an Iterator over messages to be sent to start sensors running this query

getFromQid

public byte getFromQid()

setFromQid

public void setFromQid(byte qid)

Set the id of the query this query reads results from

useRamBuffer

public void useRamBuffer(short size)

active

public boolean active()

setActive

public void setActive(boolean active)