wt.query
Class KeywordExpression

java.lang.Object
  wt.query.KeywordExpression

All Implemented Interfaces:

ColumnExpression, Expression, OrderByExpression, RelationalExpression, Serializable

public class KeywordExpression

extends Object

implements ColumnExpression, Serializable

This class represents an expression that evaluates to a SQL keyword that can be used in a SQL statement. There is no special significance to the values represented by this class. When the value evaluates to a string representation it is not quoted and cannot be replaced with a bind parameter.

Supported API: true

Extendable: false

See Also:

Serialized Form

Field Summary

private boolean	advancedQueryEnabled
static KeywordExpression	BIND_PARAMETER Constant keyword expression representing a SQL bind parameter.
private static String	CLASSNAME
static KeywordExpression	COLUMN_WILDCARD Constant keyword expression representing all columns.
private String	columnAlias
private Class	javaType
static KeywordExpression	NULL Constant keyword expression representing SQL NULL.
private static String	RESOURCE
static KeywordExpression	ROWNUM Deprecated. as of R8.0, this keyword is not standard on all datastores.
private String	value

Fields inherited from interface wt.query.ColumnExpression

ADVANCED_QUERY, ADVANCED_QUERY_ENABLED, COLUMN_ALIAS, JAVA_TYPE

Fields inherited from interface wt.query.Expression

FROM_COUNT

Constructor Summary

private	KeywordExpression()
	KeywordExpression(String a_value) Deprecated. Use newKeywordExpression(KeywordExpression)
private	KeywordExpression(String a_value, Class a_javaType)

Method Summary

Object	getBindParameter() Gets the value of the attribute: bindParameter; Returns a bind parameter for this expression (if supported).
List	getClassAttributes() Supported API: false
String	getColumnAlias() Gets the value of the attribute: columnAlias; Alias for the column expression.
String	getExpression(boolean a_useBind, Vector a_tableInfos, Vector a_aliases, boolean a_outerJoin) Return string representation of this expression.
int	getFromCount() Gets the value of the attribute: fromCount; Number of from index values that this expression requires Supported API: false
Class	getJavaType() Gets the value of the attribute: javaType; The java type of this expression.
String	getValue() Gets the value of the attribute: value; Keyword string representation.
boolean	isAdvancedQuery() Gets the value of the attribute: advancedQuery; Indicates if the expression uses advanced query capabilities.
boolean	isAdvancedQueryEnabled() Gets the value of the attribute: advancedQueryEnabled; Indicates if advanced query capabilities are enabled.
static boolean	isEqual(KeywordExpression k1, KeywordExpression k2)
static List	list(boolean a_internalUseOnly, boolean a_advancedQuery) Returns a list of available keywords.
static KeywordExpression	newKeywordExpression(KeywordExpression a_keyword) Creates a new KeywordExpression from the specified KeywordExpression constant.
static KeywordExpression	newKeywordExpression(KeywordExpression a_keyword, Class a_javaType) Creates a new KeywordExpression from the specified KeywordExpression constant and type.
void	setAdvancedQueryEnabled(boolean a_AdvancedQueryEnabled) Sets the value of the attribute: advancedQueryEnabled; Indicates if advanced query capabilities are enabled.
void	setColumnAlias(String a_ColumnAlias) Sets the value of the attribute: columnAlias; Alias for the column expression.
int	setFromAlias(String[] a_aliases, int a_offset) This method sets the FROM clause alias for this expression.
String	toString()
int	validate(TableExpression[] a_tableExpressions, int a_offset) This method validates this expression against the specified table expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

RESOURCE

private static final String RESOURCE

See Also:

Constant Field Values

CLASSNAME

private static final String CLASSNAME

value

private String value

ROWNUM

public static final KeywordExpression ROWNUM

Deprecated. as of R8.0, this keyword is not standard on all datastores.

Constant keyword expression representing ROWNUM.

Supported API: false

COLUMN_WILDCARD

public static final KeywordExpression COLUMN_WILDCARD

Constant keyword expression representing all columns.

Supported API: true

NULL

public static final KeywordExpression NULL

Constant keyword expression representing SQL NULL.

Supported API: true

BIND_PARAMETER

public static final KeywordExpression BIND_PARAMETER

Constant keyword expression representing a SQL bind parameter.

Supported API: true

javaType

private Class javaType

columnAlias

private String columnAlias

advancedQueryEnabled

private transient boolean advancedQueryEnabled

Constructor Detail

KeywordExpression

private KeywordExpression()

KeywordExpression

public KeywordExpression(String a_value)

Deprecated. Use newKeywordExpression(KeywordExpression)

Supported API: false

Parameters:

a_value - Specifies the keyword.

KeywordExpression

private KeywordExpression(String a_value,
                          Class a_javaType)

Parameters:

a_value - Specifies the keyword.

a_javaType - Java type for this keyword

Method Detail

getValue

public String getValue()

Gets the value of the attribute: value; Keyword string representation.

Supported API: false

Returns:

String

getJavaType

public Class getJavaType()
                  throws WTException

Gets the value of the attribute: javaType; The java type of this expression.

Supported API: false

Specified by:

getJavaType in interface ColumnExpression

Returns:

Class

Throws:

WTException

newKeywordExpression

public static KeywordExpression newKeywordExpression(KeywordExpression a_keyword)

Creates a new KeywordExpression from the specified KeywordExpression constant.

Supported API: true

Parameters:

a_keyword - Specifies the keyword.

Returns:

KeywordExpression

newKeywordExpression

public static KeywordExpression newKeywordExpression(KeywordExpression a_keyword,
                                                     Class a_javaType)
                                              throws WTException

Creates a new KeywordExpression from the specified KeywordExpression constant and type.

Supported API: true

Parameters:

a_keyword - Specifies the keyword.

a_javaType - Specifies the type of the Keyword expression.

Returns:

KeywordExpression

Throws:

WTException

getColumnAlias

public String getColumnAlias()

Gets the value of the attribute: columnAlias; Alias for the column expression.

Supported API: true

Specified by:

getColumnAlias in interface ColumnExpression

Returns:

String

setColumnAlias

public void setColumnAlias(String a_ColumnAlias)
                    throws WTPropertyVetoException

Sets the value of the attribute: columnAlias; Alias for the column expression.

Supported API: true

Specified by:

setColumnAlias in interface ColumnExpression

Parameters:

a_ColumnAlias -

Throws:

WTPropertyVetoException

isAdvancedQuery

public boolean isAdvancedQuery()
                        throws WTException

Gets the value of the attribute: advancedQuery; Indicates if the expression uses advanced query capabilities.

Supported API: false

Specified by:

isAdvancedQuery in interface ColumnExpression

Returns:

boolean

Throws:

WTException

isAdvancedQueryEnabled

public boolean isAdvancedQueryEnabled()

Gets the value of the attribute: advancedQueryEnabled; Indicates if advanced query capabilities are enabled.

Supported API: false

Specified by:

isAdvancedQueryEnabled in interface ColumnExpression

Returns:

boolean

setAdvancedQueryEnabled

public void setAdvancedQueryEnabled(boolean a_AdvancedQueryEnabled)

Sets the value of the attribute: advancedQueryEnabled; Indicates if advanced query capabilities are enabled.

Supported API: false

Specified by:

setAdvancedQueryEnabled in interface ColumnExpression

Parameters:

a_AdvancedQueryEnabled -

getFromCount

public int getFromCount()

Gets the value of the attribute: fromCount; Number of from index values that this expression requires

Supported API: false

Specified by:

getFromCount in interface Expression

Returns:

int

validate

public int validate(TableExpression[] a_tableExpressions,
                    int a_offset)
             throws QueryException

This method validates this expression against the specified table expression. A QueryException is thrown if this expression is not valid.

Supported API: false

Specified by:

validate in interface Expression

Parameters:

a_tableExpressions - Table expression to validate against.

a_offset - Offset index into the TableExpression array for the next valid TableExpression

Returns:

number of TableExpressions validated

Throws:

QueryException

setFromAlias

public int setFromAlias(String[] a_aliases,
                        int a_offset)

This method sets the FROM clause alias for this expression. This alias is used in this Expression in place of the corresponding TableExpression.

Supported API: false

Specified by:

setFromAlias in interface Expression

Parameters:

a_aliases - Array of aliases for expressions

a_offset - Offset index into the alias array for the next valid alias

Returns:

number of aliases used

getBindParameter

public Object getBindParameter()
                        throws WTException

Gets the value of the attribute: bindParameter; Returns a bind parameter for this expression (if supported).

Supported API: false

Specified by:

getBindParameter in interface RelationalExpression

Returns:

Object

Throws:

WTException

getExpression

public String getExpression(boolean a_useBind,
                            Vector a_tableInfos,
                            Vector a_aliases,
                            boolean a_outerJoin)
                     throws QueryException

Return string representation of this expression.

Supported API: false

Specified by:

getExpression in interface RelationalExpression

Parameters:

a_useBind - Indicates that bind variables should be used for this expression.

a_tableInfos -

a_aliases -

a_outerJoin - Indicates that outer join syntax should be used for this expression.

Returns:

String

Throws:

QueryException

getClassAttributes

public List getClassAttributes()

Supported API: false

Specified by:

getClassAttributes in interface RelationalExpression

Returns:

List

list

public static List list(boolean a_internalUseOnly,
                        boolean a_advancedQuery)

Returns a list of available keywords.

Supported API: false

Parameters:

a_internalUseOnly - indicates if keywords suitable for internal use only should be included

Returns:

List list of KeywordExpressions

isEqual

public static boolean isEqual(KeywordExpression k1,
                              KeywordExpression k2)

toString

public String toString()