oracle.javatools.db.sql

Class AbstractAliasFragment

java.lang.Object

oracle.javatools.db.AbstractDBObject

oracle.javatools.db.AbstractBuildableObject

oracle.javatools.db.AbstractChildBuildableObject

oracle.javatools.db.sql.AbstractSQLFragment

oracle.javatools.db.sql.AbstractAliasFragment

All Implemented Interfaces:

ChildDBObject, DBObject, AliasFragment, SQLFragment, Copyable

Direct Known Subclasses:

FromObject, SelectObject

public abstract class AbstractAliasFragment
extends AbstractSQLFragment
implements AliasFragment

SQLFragment that consists of an expression and an alias.

Since:

10.1.3

Nested Class Summary

Nested classes/interfaces inherited from class oracle.javatools.db.AbstractDBObject

AbstractDBObject.ChildSupport, AbstractDBObject.ListenerSupport

Field Summary

Fields inherited from class oracle.javatools.db.sql.AbstractSQLFragment

AS, COMMA, DEFAULT_SEPARATOR, EMPTY, EMPTY_ARRAY, INDENT, LEFT_PAREN, NEWLINE, RIGHT_PAREN, SPACE

Fields inherited from interface oracle.javatools.db.sql.SQLFragment

CONNECTBY, FROM, GROUPBY, HAVING, MODEL, NOCYCLE, ORDERBY, ORDERSIBLINGSBY, PRIOR, SELECT, STARTWITH, TYPE, WHERE

Fields inherited from interface oracle.javatools.db.DBObject

COMMENT

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractAliasFragment() Creates an empty fragment.
protected	AbstractAliasFragment(SQLFragment exp, java.lang.String alias) Creates a fragment with given expression and alias.

Method Summary

Modifier and Type	Method and Description
boolean	canHaveAlias() In certain circumstances an AliasFragment cannot have an alias.
protected boolean	canUseAsAlias(java.lang.String exp) Checks whether the given expression can be used as an alias.
java.lang.String	getAlias() Returns the alias portion of this SQLFragment.
SQLFragment	getExpression() Returns the expression portion of this SQLFragment.
java.lang.String	getName() Gets a "name" for this fragment.
java.lang.String	getSQLText() Returns the entire fragment (expression plus alias in external form).
java.lang.String	getUsableAlias() Obtains a String that can be used as an alias to this fragment.
void	setAlias(java.lang.String alias) Sets the alias part of the fragment.
void	setExpression(SQLFragment expression) Sets the expression part of the fragment.
java.lang.String	toString()
protected boolean	useAsBeforeAlias() Returns true if the current fragment should have an AS between expression and alias.

Methods inherited from class oracle.javatools.db.sql.AbstractSQLFragment

appendToBuffer, appendToBuffer, argsToString, getStartOffset, getTextOrNull, getTextOrNull, getType, setStartOffset, surroundWithBrackets, surroundWithBrackets

Methods inherited from class oracle.javatools.db.AbstractChildBuildableObject

setParent

Methods inherited from class oracle.javatools.db.AbstractBuildableObject

checkInit, checkInit, copyToImpl, getOwnedObjectsImpl, getProperties, getReferenceIDsImpl, needsInitialization, processPropertyChange, setID

Methods inherited from class oracle.javatools.db.AbstractDBObject

addObjectListener, addObjectListener, addObjectListener, changeParent, compareToImpl, copyObject, copyTo, copyTo, copyTo, copyTo, equals, equalsImpl, findOwnedObject, findOwnedObject, findOwnedObject, findOwnedObject, findParent, fireObjectUpdated, firePropertyChanged, getChildSupport, getChildSupport, getID, getOwnedObjects, getOwnedObjects, getParent, getProperty, getProperty, getReferenceIDs, hashCode, includeOwnedObject, includesType, includesType, removeObjectListener, removeObjectListener, removeObjectListener, removeOwnedObject, removeThisAsParent, replaceReferenceIDs, setName, setProperties, setProperty

Methods inherited from class java.lang.Object

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

Methods inherited from interface oracle.javatools.db.sql.SQLFragment

getStartOffset

Methods inherited from interface oracle.javatools.db.ChildDBObject

getParent, setParent

Methods inherited from interface oracle.javatools.db.DBObject

addObjectListener, copyTo, copyTo, copyTo, equals, findOwnedObject, findOwnedObject, findOwnedObject, getID, getOwnedObjects, getOwnedObjects, getProperties, getProperty, getProperty, getReferenceIDs, getType, hashCode, removeObjectListener, removeOwnedObject, replaceReferenceIDs, setID, setName, setProperties, setProperty

Constructor Detail

AbstractAliasFragment

protected AbstractAliasFragment()

Creates an empty fragment.

AbstractAliasFragment

protected AbstractAliasFragment(SQLFragment exp,
                                java.lang.String alias)

Creates a fragment with given expression and alias. The alias name should be in its external form, i.e. be quoted if necessary

Method Detail

getAlias

public java.lang.String getAlias()

Returns the alias portion of this SQLFragment.

Specified by:

getAlias in interface AliasFragment

setAlias

public void setAlias(java.lang.String alias)

Sets the alias part of the fragment. The alias name should be in its external form, i.e. be quoted if necessary

Specified by:

setAlias in interface AliasFragment

canHaveAlias

public boolean canHaveAlias()

In certain circumstances an AliasFragment cannot have an alias. This method returns false if that is the case.

getExpression

public SQLFragment getExpression()

Returns the expression portion of this SQLFragment.

Specified by:

getExpression in interface AliasFragment

setExpression

public void setExpression(SQLFragment expression)

Sets the expression part of the fragment.

Specified by:

setExpression in interface AliasFragment

getSQLText

public java.lang.String getSQLText()

Returns the entire fragment (expression plus alias in external form).

Specified by:

getSQLText in interface AliasFragment

Specified by:

getSQLText in interface SQLFragment

Returns:

a string representing the SQL text for this object.

useAsBeforeAlias

protected boolean useAsBeforeAlias()

Returns true if the current fragment should have an AS between expression and alias. Returns false by default, subclasses override if appropraite.

getUsableAlias

public java.lang.String getUsableAlias()

Description copied from interface: AliasFragment

Obtains a String that can be used as an alias to this fragment. Can return null if there is no alias set, and the expression is not a valid alias. DBObject names are in external form. This is different to getName() because that will always return the expression even if it is not a valid alias.

Specified by:

getUsableAlias in interface AliasFragment

Returns:

the alias if there is one, otherwise the expression text if it could be a valid alias.

getName

public java.lang.String getName()

Gets a "name" for this fragment. This can call getSQLText() so is a potentially expensive operation.

Specified by:

getName in interface DBObject

Overrides:

getName in class AbstractSQLFragment

Returns:

the alias if there is one or the expression. NOTE the expression may not be a valid alias depending on the flavour of SQL.

canUseAsAlias

protected boolean canUseAsAlias(java.lang.String exp)

Checks whether the given expression can be used as an alias.

toString

public java.lang.String toString()

Overrides:

toString in class AbstractSQLFragment