Package net.sf.basedb.core

Class DynamicJoin

java.lang.Object

net.sf.basedb.core.DynamicJoin

All Implemented Interfaces:

Join, QueryElement

class DynamicJoin
extends Object
implements Join

Represents a join between two virtual tables in a dynamic query: leftTable JOIN rightTable ON columns.

This class is used by, for example, DynamicSpotQuery.joinReporters(JoinType) to create the Join query element that is needed.

Version:

2.0

Author:

Nicklas

Last modified

$Date: 2012-09-14 09:28:35 +0200 (fr, 14 sep 2012) $

Field Summary

Fields

Modifier and Type	Field	Description
private int	hashCode
private final JoinType	joinType
private final VirtualTable	left
private final VirtualColumn[]	leftColumns
private final VirtualTable	right
private final VirtualColumn[]	rightColumns
private final VirtualDb	vdb

Constructor Summary

Constructors

Constructor	Description
DynamicJoin(VirtualDb vdb, JoinType joinType, VirtualTable right, VirtualColumn... columns)	Create a new join using the root entity table as the left table.
DynamicJoin(VirtualDb vdb, JoinType joinType, VirtualTable left, VirtualColumn[] leftColumns, VirtualTable right, VirtualColumn[] rightColumns)	Create a new join between two tables with possible different colum names in the left and right tables.
DynamicJoin(VirtualDb vdb, JoinType joinType, VirtualTable left, VirtualTable right, VirtualColumn... columns)	Create a new join between two tables.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)	This join is equal to another DynamicJoin if they join between the same tables using the same columns and join types.
Collection<? extends QueryElement>	getChildren()	Get the children of this query element or null if it has no children.
String	getThetaJoin(Query query, DbControl dc)
String	getThetaJoinCondition(Query query, DbControl dc)
int	hashCode()
String	toQl(Query query, DbControl dc)	Create a query language string of the query element.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

vdb

private final VirtualDb vdb

joinType

private final JoinType joinType

left

private final VirtualTable left

right

private final VirtualTable right

leftColumns

private final VirtualColumn[] leftColumns

rightColumns

private final VirtualColumn[] rightColumns

hashCode

private int hashCode

Constructor Details

DynamicJoin

DynamicJoin(VirtualDb vdb,
 JoinType joinType,
 VirtualTable right,
 VirtualColumn... columns)

Create a new join using the root entity table as the left table. SELECT ... FROM rootTable JOIN right ON columns.

Parameters:

vdb - The virtual database where the joined table is located

joinType - The type of join

right - The table to join to

columns - The columns to join on, all columns must exists in the root table and the joined table

DynamicJoin

DynamicJoin(VirtualDb vdb,
 JoinType joinType,
 VirtualTable left,
 VirtualTable right,
 VirtualColumn... columns)

Create a new join between two tables. The left table must already have been joined to the root table or to another joined table. SELECT ... FROM rootTable ... JOIN left ... JOIN right ON columns

Parameters:

vdb - The virtual database where the joined table is located

joinType - The type of join

left - The table to join from

right - The table to join to

columns - The columns to join on, all columns must exists in the left table and the right table

DynamicJoin

DynamicJoin(VirtualDb vdb,
 JoinType joinType,
 VirtualTable left,
 VirtualColumn[] leftColumns,
 VirtualTable right,
 VirtualColumn[] rightColumns)

Create a new join between two tables with possible different colum names in the left and right tables.

Parameters:

vdb - The virtual database where the joined table is located

joinType - The type of join

left - The table to join from (or null to join from the root table)

leftColumns - The columns in the left table to use in the join

right - The table to join to

rightColumns - The columns in the right table (must be of same length as leftColumns)

Since:

3.1

Method Details

toQl

public String toQl(Query query,
 DbControl dc)
            throws BaseException

Description copied from interface: QueryElement

Create a query language string of the query element. Use the Query.getQueryType() method to find out which query language is wanted in case the element requires different syntax for different languages.

Specified by:

toQl in interface QueryElement

Parameters:

query - The query that is about to be executed

dc - The DbControl object used to execute the query

Throws:

BaseException - If there is any other error

getChildren

public Collection<? extends QueryElement> getChildren()

Description copied from interface: QueryElement

Get the children of this query element or null if it has no children. For example the AddExpression has two children, the expression beeing added.

Specified by:

getChildren in interface QueryElement

Returns:

Always null

getThetaJoin

public String getThetaJoin(Query query,
 DbControl dc)
                    throws BaseException

Specified by:

getThetaJoin in interface Join

Throws:

BaseException

getThetaJoinCondition

public String getThetaJoinCondition(Query query,
 DbControl dc)
                             throws BaseException

Specified by:

getThetaJoinCondition in interface Join

Throws:

BaseException

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object other)

This join is equal to another DynamicJoin if they join between the same tables using the same columns and join types.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object