org.teiid.query.sql.symbol

Class ElementSymbol

java.lang.Object

org.teiid.query.sql.symbol.Symbol

org.teiid.query.sql.symbol.ElementSymbol

All Implemented Interfaces:

Cloneable, LanguageObject, DerivedExpression, Expression

public class ElementSymbol
extends Symbol
implements DerivedExpression

This is a subclass of Symbol representing a single element. An ElementSymbol also is an expression and thus has a type. Element symbols have a variety of attributes that determine how they are displayed - a flag for displaying fully qualified and an optional vdb name.

The "isExternalReference" property indicates whether the element symbol refers to an element from a group outside the current command. Typically this is set to false. Common uses when this is set to true are for variables used within a command, correlated elements within a command, etc.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ElementSymbol.DisplayMode

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

LanguageObject.Util

Field Summary

Fields inherited from class org.teiid.query.sql.symbol.Symbol

outputName, SEPARATOR

Constructor Summary

Constructors

Constructor and Description
ElementSymbol(String name) Simple constructor taking just a name.
ElementSymbol(String name, boolean displayFullyQualified) Constructor taking a name and a flag whether to display fully qualified.
ElementSymbol(String shortName, GroupSymbol group)
ElementSymbol(String shortName, GroupSymbol group, Class<?> type)

Method Summary

Modifier and Type	Method and Description
void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
ElementSymbol	clone() Return a deep copy of this object.
boolean	equals(Object obj) Compare the symbol based ONLY on name.
boolean	getDisplayFullyQualified() Get whether this element will be displayed as fully qualified
ElementSymbol.DisplayMode	getDisplayMode()
GroupSymbol	getGroupSymbol() Get the group symbol referred to by this element symbol, may be null before resolution
Object	getMetadataID() Get the metadata ID reference
String	getName() Get the name of the symbol
Class<?>	getType() Get the type of the symbol
int	hashCode() Return a hash code for this symbol.
boolean	isAggregate()
boolean	isExternalReference() Get whether this element is an external reference to a group outside the command context.
void	setAggregate(boolean isAggregate)
void	setDisplayFullyQualified(boolean displayFullyQualified) Set whether this element will be displayed as fully qualified
void	setDisplayMode(ElementSymbol.DisplayMode displayMode)
void	setGroupSymbol(GroupSymbol symbol) Set the group symbol referred to by this element symbol
void	setIsExternalReference(boolean isExternalReference) Set whether this element is an external reference.
void	setMetadataID(Object metadataID) Set the metadata ID reference for this element
protected void	setName(String name)
void	setType(Class<?> type) Set the type of the symbol

Methods inherited from class org.teiid.query.sql.symbol.Symbol

getName, getOutputName, getOutputName, getShortName, getShortName, getShortName, setOutputName, setShortName, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ElementSymbol

public ElementSymbol(String name)

Simple constructor taking just a name. By default will display fully qualified name

Parameters:

name - Name of the symbol, may or may not be fully qualified

ElementSymbol

public ElementSymbol(String shortName,
                     GroupSymbol group)

ElementSymbol

public ElementSymbol(String shortName,
                     GroupSymbol group,
                     Class<?> type)

ElementSymbol

public ElementSymbol(String name,
                     boolean displayFullyQualified)

Constructor taking a name and a flag whether to display fully qualified.

Parameters:

name - Name of the symbol

displayFullyQualified - True if should display fully qualified

Method Detail

getName

public String getName()

Description copied from class: Symbol

Get the name of the symbol

Overrides:

getName in class Symbol

Returns:

Name of the symbol, never null

equals

public boolean equals(Object obj)

Description copied from class: Symbol

Compare the symbol based ONLY on name. Symbols are not compared based on their underlying physical metadata IDs but rather on their representation in the context of a particular query. Case is not important when comparing symbol names.

Overrides:

equals in class Symbol

Parameters:

obj - Other object

Returns:

True if other obj is a Symbol (or subclass) and name is equal

hashCode

public int hashCode()

Description copied from class: Symbol

Return a hash code for this symbol.

Overrides:

hashCode in class Symbol

Returns:

Hash code

setDisplayMode

public void setDisplayMode(ElementSymbol.DisplayMode displayMode)

getDisplayMode

public ElementSymbol.DisplayMode getDisplayMode()

setDisplayFullyQualified

public void setDisplayFullyQualified(boolean displayFullyQualified)

Set whether this element will be displayed as fully qualified

Parameters:

displayFullyQualified - True if should display fully qualified

getDisplayFullyQualified

public boolean getDisplayFullyQualified()

Get whether this element will be displayed as fully qualified

Returns:

True if should display fully qualified

setIsExternalReference

public void setIsExternalReference(boolean isExternalReference)

Set whether this element is an external reference. An external reference is an element that comes from a group outside the current command context. Typical uses would be variables and correlated references in subqueries.

Parameters:

isExternalReference - True if element is an external reference

isExternalReference

public boolean isExternalReference()

Get whether this element is an external reference to a group outside the command context.

Returns:

True if element is an external reference

setGroupSymbol

public void setGroupSymbol(GroupSymbol symbol)

Set the group symbol referred to by this element symbol

Parameters:

symbol - the group symbol to set

setName

protected void setName(String name)

Overrides:

setName in class Symbol

getGroupSymbol

public GroupSymbol getGroupSymbol()

Get the group symbol referred to by this element symbol, may be null before resolution

Returns:

Group symbol referred to by this element, may be null

getMetadataID

public Object getMetadataID()

Get the metadata ID reference

Returns:

Metadata ID reference, may be null before resolution

setMetadataID

public void setMetadataID(Object metadataID)

Set the metadata ID reference for this element

Parameters:

metadataID - Metadata ID reference

getType

public Class<?> getType()

Get the type of the symbol

Specified by:

getType in interface Expression

Returns:

Type of the symbol, may be null before resolution

setType

public void setType(Class<?> type)

Set the type of the symbol

Parameters:

type - New type

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

clone

public ElementSymbol clone()

Return a deep copy of this object.

Specified by:

clone in interface LanguageObject

Specified by:

clone in class Symbol

Returns:

Deep copy of this object

isAggregate

public boolean isAggregate()

setAggregate

public void setAggregate(boolean isAggregate)