EVEDemo.SWEEP
Class Relation

java.lang.Object
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  +--EVEDemo.SWEEP.Element
        |
        +--EVEDemo.SWEEP.StampedElement
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              +--EVEDemo.SWEEP.Relation

Direct Known Subclasses:

ViewDefinition

public class Relation

extends StampedElement

implements java.io.Serializable, java.lang.Cloneable

This is a class represent a Relational Database Table. We can create it from: 1. null 2. ResultSet from JDBC 3. File created by write() method We can following operations on it: 1. Join 2. Plus 3. Minus 4. Projection 5. delColumn Tuple Format: (values)[number] e.g. (5,6)[3] means we have three duplicate (5,6) tuples.

See Also:

Serialized Form

Field Summary

(package private) java.lang.String	alias Alias of this Relation.
(package private) static int	objnum debug variable to trace how many relation object created.
(package private) RelationExtent	theExtent
(package private) java.lang.String	theName
(package private) RelationSchema	theSchema

Fields inherited from class EVEDemo.SWEEP.StampedElement

id, TimeStamp

Constructor Summary

private	Relation()
	Relation(java.io.FileInputStream fin)
	Relation(java.sql.ResultSet rs, java.lang.String newName) this is a constructor of Relation from result set.
	Relation(java.sql.ResultSet rs, java.lang.String newName, Relation localrel, java.lang.String sign) This constructor will create a Relation from Resultset.
	Relation(java.sql.ResultSet rs, java.lang.String newName, java.lang.String sign) This constructor will create a Relation from Resultset.
	Relation(java.sql.ResultSet rs, java.lang.String newName, java.lang.String sign1, java.lang.String sign2) This constructor will create a Relation from Resultset.
	Relation(java.lang.String newName)

Method Summary

java.lang.Object	clone()
java.lang.String	createTableSQL()
java.lang.String	createTableSQL(java.lang.String sign) This function will create a table with sign field.
void	delCol(java.lang.String colName) Delete one column from the Relation
void	finalize()
java.lang.String	getAlias()
int	getCardinality()
java.lang.String	getCommon(Relation theRelation)
RelationExtent	getExtent()
java.lang.String	getName()
RelationSchema	getSchema() get Schema of this Relation.
void	initIterator() Cooperate with moreTuple and InsertTupleSQL, TupleSQL.
void	insertTuple(Tuple newTuple)
int	insertTupleSQL(java.lang.StringBuffer Query) Cooperate with moreTuple and initIterator.
int	insertTupleSQL(java.lang.StringBuffer Query, java.lang.String sign) Cooperate with moreTuple and initIterator.
Relation	join(Relation sndRelation) This method will join two relations and return the result.
Relation	joinVirtual(Relation sndRelation) This method will join two relations and return the result.
Relation	joinVirtualOn(Relation sndRelation, java.util.Hashtable JCAttrs) This method will join two relations and return the result.
private java.lang.String	makeConditions(java.lang.StringBuffer tupleValues) This function will generate the conditions from Relation Schema and the Tuple This function should be only used by method: insertTupleSQL().
Relation	minus(Relation sndRelation)
boolean	moreTuple() Cooperate with initIterator and InsertTupleSQL, TupleSQL.
Relation	plus(Relation sndRelation)
void	projectOn(Relation Rel) Do Project Operation.
void	rename(java.lang.String newName) Give this Relation a new name
void	setAlias(java.lang.String newname)
void	setExtent(RelationExtent newExtent) This function set the new extent of this relation.
void	setName(java.lang.String newName) Set New name for this relation.
void	setSchema(RelationSchema newSchema)
java.lang.String	toString() Convert Relation to String
int	updateTupleSQL(java.lang.StringBuffer Query) Cooperate with moreTuple and initIterator.
void	write(java.io.FileOutputStream fout)

Methods inherited from class EVEDemo.SWEEP.StampedElement

getTimeStamp, OlderThan, setTimeStamp

Methods inherited from class java.lang.Object

, equals, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Field Detail

theName

java.lang.String theName

alias

java.lang.String alias

Alias of this Relation. It used for Join Condition to keep track of Where this Relation comes from.

theSchema

RelationSchema theSchema

theExtent

RelationExtent theExtent

objnum

static int objnum

debug variable to trace how many relation object created.

Constructor Detail

Relation

private Relation()

Relation

public Relation(java.sql.ResultSet rs,
                java.lang.String newName)
         throws java.lang.Exception

this is a constructor of Relation from result set.

Relation

public Relation(java.sql.ResultSet rs,
                java.lang.String newName,
                java.lang.String sign)
         throws java.lang.Exception

This constructor will create a Relation from Resultset. Important part here, is that this constructor will search for the "SWEEPSIGN" field. if it is 'p', means positive; if it is 'n', means negative.

Relation

public Relation(java.sql.ResultSet rs,
                java.lang.String newName,
                Relation localrel,
                java.lang.String sign)
         throws java.lang.Exception

This constructor will create a Relation from Resultset. Important part here, is that this constructor will search for the "SWEEPSIGN" field. if it is 'p', means positive; if it is 'n', means negative.

Relation

public Relation(java.sql.ResultSet rs,
                java.lang.String newName,
                java.lang.String sign1,
                java.lang.String sign2)
         throws java.lang.Exception

This constructor will create a Relation from Resultset. Important part here, is that this constructor will search for the "SWEEPSIGN1" field and "SWEEPSIGN2" field. if they are same, means positive; otherwise, means negative.

Relation

public Relation(java.lang.String newName)

Relation

public Relation(java.io.FileInputStream fin)

Method Detail

finalize

public void finalize()

Overrides:

finalize in class java.lang.Object

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

setExtent

public void setExtent(RelationExtent newExtent)

This function set the new extent of this relation. It should check the consistency of current schema and current extent, but I haven't implement it.

getAlias

public java.lang.String getAlias()

setAlias

public void setAlias(java.lang.String newname)

setSchema

public void setSchema(RelationSchema newSchema)

insertTuple

public void insertTuple(Tuple newTuple)
                 throws java.lang.Exception

createTableSQL

public java.lang.String createTableSQL()

createTableSQL

public java.lang.String createTableSQL(java.lang.String sign)

This function will create a table with sign field. e.g. "col1, col2" will be "SWEEPSIGN, col1, col2"

initIterator

public void initIterator()

Cooperate with moreTuple and InsertTupleSQL, TupleSQL.

moreTuple

public boolean moreTuple()

Cooperate with initIterator and InsertTupleSQL, TupleSQL.

updateTupleSQL

public int updateTupleSQL(java.lang.StringBuffer Query)

Cooperate with moreTuple and initIterator. This function is only used for Create Temporary Table in Oracle. So, this function will ASSUME all the QUERYNUMBER should be POSITIVE. if the QUERYNUMBER is negative, it will genereate "delete" query.

insertTupleSQL

public int insertTupleSQL(java.lang.StringBuffer Query)

Cooperate with moreTuple and initIterator. This function is only used for Create Temporary Table in Oracle. So, this function will ASSUME all the QUERYNUMBER should be POSITIVE. if the QUERYNUMBER is negative, it will genereate "delete" query.

insertTupleSQL

public int insertTupleSQL(java.lang.StringBuffer Query,
                          java.lang.String sign)

Cooperate with moreTuple and initIterator. This function is only used for Create Temporary Table in Oracle. So, this function will ASSUME all the QUERYNUMBER should be POSITIVE. if the QUERYNUMBER is negative, it will genereate "delete" query.

makeConditions

private java.lang.String makeConditions(java.lang.StringBuffer tupleValues)
                                 throws java.lang.Exception

This function will generate the conditions from Relation Schema and the Tuple This function should be only used by method: insertTupleSQL(). The input stringbuffer should fit in such format: value1,value2,value3

getName

public java.lang.String getName()

getCommon

public java.lang.String getCommon(Relation theRelation)

getExtent

public RelationExtent getExtent()

write

public void write(java.io.FileOutputStream fout)

minus

public Relation minus(Relation sndRelation)
               throws java.lang.Exception

plus

public Relation plus(Relation sndRelation)

join

public Relation join(Relation sndRelation)

This method will join two relations and return the result. It is assumed the second Relation is already in the database.

joinVirtual

public Relation joinVirtual(Relation sndRelation)

This method will join two relations and return the result. It is assumed both relation are not on the database.

joinVirtualOn

public Relation joinVirtualOn(Relation sndRelation,
                              java.util.Hashtable JCAttrs)

This method will join two relations and return the result. It is assumed both relation are not on the database.

getCardinality

public int getCardinality()

toString

public java.lang.String toString()

Convert Relation to String

Overrides:

toString in class java.lang.Object

rename

public void rename(java.lang.String newName)

Give this Relation a new name

projectOn

public void projectOn(Relation Rel)
               throws java.lang.Exception

Do Project Operation. Project will project this relation on specific relation's schema. Here the new Relation's schema must be a subset of this relation's schema.

getSchema

public RelationSchema getSchema()

get Schema of this Relation.

setName

public void setName(java.lang.String newName)

Set New name for this relation.

delCol

public void delCol(java.lang.String colName)

Delete one column from the Relation