Oracle Fusion Middleware Java API Reference for Oracle TopLink
11g Release 1 (11.1.1)

E28847-01


org.eclipse.persistence.jpa.internal.jpql.parser
Class ResultVariable

java.lang.Object
  extended by org.eclipse.persistence.jpa.internal.jpql.parser.StringExpression
      extended by org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression
          extended by org.eclipse.persistence.jpa.internal.jpql.parser.ResultVariable

All Implemented Interfaces:
Expression

public final class ResultVariable
extends AbstractExpression

A result variable may be used to name a select item in the query result.

BNF: select_item ::= select_expression [[AS] result_variable]
Since:
2.3
Version:
2.3
Author:
Pascal Filion

Field Summary
private  boolean hasAs
          Determines whether the identifier AS was parsed or not.
private  boolean hasSpaceAfterAs
          Determines whether a whitespace was parsed after the identifier AS.
private  AbstractExpression resultVariable
          The Expression used
private  AbstractExpression selectExpression
          The Expression representing the select expression.
 
Fields inherited from class org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression
COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE
 
Fields inherited from interface org.eclipse.persistence.jpa.internal.jpql.parser.Expression
ABS, ALL, AND, ANY, AS, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, CONCAT, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXISTS, FALSE, FETCH, FROM, FUNC, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LEADING, LEFT, LEFT_JOIN, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN, LEFT_OUTER_JOIN_FETCH, LENGTH, LIKE, LOCATE, LOWER, LOWER_THAN, LOWER_THAN_OR_EQUAL, MAX, MEMBER, MEMBER_OF, MIN, MINUS, MOD, MULTIPLICATION, NAMED_PARAMETER, NEW, NOT, NOT_BETWEEN, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, OBJECT, OF, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, SELECT, SET, SIZE, SOME, SQRT, SUBSTRING, SUM, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE
 
Constructor Summary
ResultVariable(AbstractExpression parent, AbstractExpression selectExpression)
          Creates a new ResultVariable.
 
Method Summary
 void accept(ExpressionVisitor visitor)
          Visits this Expression by the given visitor.
 void acceptChildren(ExpressionVisitor visitor)
          Visits the children of this Expression.
(package private)  void addChildrenTo(java.util.Collection<Expression> children)
          Adds the children of this Expression to the given collection.
(package private)  void addOrderedChildrenTo(java.util.List<StringExpression> children)
          Adds the StringExpressions representing this Expression.
 JPQLQueryBNF getQueryBNF()
          Returns the BNF of this Expression.
 Expression getResultVariable()
          Returns the Expression representing the result variable.
 Expression getSelectExpression()
          Returns the Expression representing the select expression.
 boolean hasAs()
          Determines whether the identifier AS was parsed or not.
 boolean hasResultVariable()
          Determines whether the result variable was parsed.
 boolean hasSelectExpression()
          Determines whether a select expression was defined for this result variable.
 boolean hasSpaceAfterAs()
          Determines whether a whitespace was parsed after the identifier AS.
(package private)  void parse(WordParser wordParser, boolean tolerant)
          Parses the query by starting at the current position, which is part of the given WordParser.
(package private)  void toParsedText(java.lang.StringBuilder writer, boolean includeVirtual)
          Generates a string representation of this Expression.
 
Methods inherited from class org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression
buildExpressionFromFallingBack, buildNullExpression, buildStringExpression, buildStringExpression, buildUnknownExpression, children, expressionFactory, expressionFactoryForIdentifier, findQueryBNF, getChildren, getJPAVersion, getParent, getRoot, getText, handleAggregate, identifierRole, identifiers, identifiers, identifierVersion, isAncestor, isIdentifier, isNull, isParsingComplete, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseSingleExpression, populatePosition, queryBNF, readdLeadingSpaces, rebuildActualText, rebuildParsedText, setParent, setText, shouldParseWithFactoryFirst, shouldSkipLiteral, toActualText, toParsedText, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

hasAs

private boolean hasAs
Determines whether the identifier AS was parsed or not.

hasSpaceAfterAs

private boolean hasSpaceAfterAs
Determines whether a whitespace was parsed after the identifier AS.

resultVariable

private AbstractExpression resultVariable
The Expression used

selectExpression

private AbstractExpression selectExpression
The Expression representing the select expression.
Constructor Detail

ResultVariable

ResultVariable(AbstractExpression parent,
               AbstractExpression selectExpression)
Creates a new ResultVariable.
Parameters:
parent - The parent of this expression
selectExpression - The expression that represents the select expression, which will have a variable assigned to it
Method Detail

accept

public void accept(ExpressionVisitor visitor)
Visits this Expression by the given visitor.
Parameters:
visitor - The visitor to visit this object

acceptChildren

public void acceptChildren(ExpressionVisitor visitor)
Visits the children of this Expression. This method can be used to optimize traversing the children since a new list is not created every time Expression.children() or Expression.getChildren() is called.

This does not traverse the Expression sub-hierarchy, use an subclass of AbstractTraverseChildrenVisitor in order to traverse the entire sub-hierarchy.

Parameters:
visitor - The visitor to visit the children of this object.

addChildrenTo

void addChildrenTo(java.util.Collection<Expression> children)
Adds the children of this Expression to the given collection.
Overrides:
addChildrenTo in class AbstractExpression
Parameters:
children - The collection used to store the children

addOrderedChildrenTo

void addOrderedChildrenTo(java.util.List<StringExpression> children)
Adds the StringExpressions representing this Expression.
Overrides:
addOrderedChildrenTo in class AbstractExpression
Parameters:
children - The list used to store the string representation of this Expression

getQueryBNF

public JPQLQueryBNF getQueryBNF()
Returns the BNF of this Expression.
Specified by:
getQueryBNF in class AbstractExpression
Returns:
The JPQLQueryBNF, which represents the grammar of this Expression

getResultVariable

public Expression getResultVariable()
Returns the Expression representing the result variable.
Returns:
The expression for the result variable

getSelectExpression

public Expression getSelectExpression()
Returns the Expression representing the select expression.
Returns:
The expression for the select expression

hasAs

public boolean hasAs()
Determines whether the identifier AS was parsed or not.
Returns:
true if the identifier AS was parsed; false otherwise

hasResultVariable

public boolean hasResultVariable()
Determines whether the result variable was parsed.
Returns:
true if the result variable was parsed; false otherwise

hasSelectExpression

public boolean hasSelectExpression()
Determines whether a select expression was defined for this result variable.
Returns:
true if the select expression was parsed; false if the result variable was parsed without one

hasSpaceAfterAs

public boolean hasSpaceAfterAs()
Determines whether a whitespace was parsed after the identifier AS.
Returns:
true if there was a whitespace after AS; false otherwise

parse

void parse(WordParser wordParser,
           boolean tolerant)
Parses the query by starting at the current position, which is part of the given WordParser.
Specified by:
parse in class AbstractExpression
Parameters:
wordParser - The text to parse based on the current position of the cursor
tolerant - Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries

toParsedText

void toParsedText(java.lang.StringBuilder writer,
                  boolean includeVirtual)
Generates a string representation of this Expression.
Specified by:
toParsedText in class AbstractExpression
Parameters:
writer - The buffer used to append this Expression's string representation
includeVirtual - Determines whether to include any characters that are considered virtual, i.e. that was parsed when the query is incomplete and is needed for functionality like content assist

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