org.teiid.query.sql.lang

Class JoinType

java.lang.Object

org.teiid.query.sql.lang.JoinType

All Implemented Interfaces:

Cloneable, LanguageObject

public class JoinType
extends Object
implements LanguageObject

This class represents a join type. Outer joins will put nulls on the outer side for non-matches. "Cross" joins have no criteria and are a cross product of all rows in each table. To use a JoinType, you should not (and cannot) construct the object - rather you should use the provided static constants.

Nested Class Summary

Nested classes/interfaces inherited from interface org.teiid.query.sql.LanguageObject

LanguageObject.Util

Field Summary

Fields

Modifier and Type	Field and Description
static JoinType	JOIN_ANTI_SEMI internal ANTI SEMI Join type
static JoinType	JOIN_CROSS Represents a cross join: a CROSS JOIN b
static JoinType	JOIN_FULL_OUTER Represents a full outer join: a FULL OUTER JOIN b
static JoinType	JOIN_INNER Represents an inner join: a INNER JOIN b
static JoinType	JOIN_LEFT_OUTER Represents a left outer join: a LEFT OUTER JOIN b
static JoinType	JOIN_RIGHT_OUTER Represents a right outer join: a RIGHT OUTER JOIN b
static JoinType	JOIN_SEMI internal SEMI Join type
static JoinType	JOIN_UNION Represents a union join: a UNION JOIN b - not used after rewrite

Method Summary

Modifier and Type	Method and Description
void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
Object	clone() Class is immutable, so clone can just return the same class
boolean	equals(Object other) Override Object.equals() to compare objects
JoinType	getReverseType() To switch directions from left to right or right to left.
int	hashCode() Get hash code for this type
boolean	isOuter() Check if this join type is an outer join.
String	toString() Returns a string representation of an instance of this class.

Methods inherited from class java.lang.Object

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

Field Detail

JOIN_INNER

public static final JoinType JOIN_INNER

Represents an inner join: a INNER JOIN b

JOIN_RIGHT_OUTER

public static final JoinType JOIN_RIGHT_OUTER

Represents a right outer join: a RIGHT OUTER JOIN b

JOIN_LEFT_OUTER

public static final JoinType JOIN_LEFT_OUTER

Represents a left outer join: a LEFT OUTER JOIN b

JOIN_FULL_OUTER

public static final JoinType JOIN_FULL_OUTER

Represents a full outer join: a FULL OUTER JOIN b

JOIN_CROSS

public static final JoinType JOIN_CROSS

Represents a cross join: a CROSS JOIN b

JOIN_UNION

public static final JoinType JOIN_UNION

Represents a union join: a UNION JOIN b - not used after rewrite

JOIN_SEMI

public static final JoinType JOIN_SEMI

internal SEMI Join type

JOIN_ANTI_SEMI

public static final JoinType JOIN_ANTI_SEMI

internal ANTI SEMI Join type

Method Detail

getReverseType

public JoinType getReverseType()

To switch directions from left to right or right to left. Joins that are not LEFT OUTER or RIGHT OUTER are returned unchanged.

Returns:

New JoinType constant for the reverse join type

isOuter

public boolean isOuter()

Check if this join type is an outer join.

Returns:

True if left/right/full outer, false if inner/cross

equals

public boolean equals(Object other)

Override Object.equals() to compare objects

Overrides:

equals in class Object

Parameters:

other - Other object

Returns:

True if equal

acceptVisitor

public void acceptVisitor(LanguageVisitor visitor)

Description copied from interface: LanguageObject

Method for accepting a visitor. It is the responsibility of the language object to call back on the visitor.

Specified by:

acceptVisitor in interface LanguageObject

Parameters:

visitor - Visitor being used

hashCode

public int hashCode()

Get hash code for this type

Overrides:

hashCode in class Object

Returns:

Hash code

clone

public Object clone()

Class is immutable, so clone can just return the same class

Specified by:

clone in interface LanguageObject

Overrides:

clone in class Object

Returns:

Same object - these objects are immutable

toString

public String toString()

Returns a string representation of an instance of this class.

Overrides:

toString in class Object

Returns:

String representation of object