org.eclipse.persistence.jpa.jpql.parser
Class CoalesceExpression

java.lang.Object
  org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
      org.eclipse.persistence.jpa.jpql.parser.AbstractEncapsulatedExpression
          org.eclipse.persistence.jpa.jpql.parser.AbstractSingleEncapsulatedExpression
              org.eclipse.persistence.jpa.jpql.parser.CoalesceExpression

All Implemented Interfaces:

Expression

public final class CoalesceExpression
extends AbstractSingleEncapsulatedExpression

A COALESCE expression returns null if all its arguments evaluate to null, and the value of the first non-null argument otherwise.

The return type is the type returned by the arguments if they are all of the same type, otherwise it is undetermined.

BNF: coalesce_expression::= COALESCE(scalar_expression {, scalar_expression}+)

Version:

2.4

Author:

Pascal Filion

Since:

2.3

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.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.jpql.parser.Expression

ABS, ALL, AND, ANY, AS, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXCEPT, EXISTS, EXTRACT, FALSE, FETCH, FROM, FUNC, FUNCTION, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, INTERSECT, 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_EQUAL, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SELECT, SET, SIZE, SOME, SQL, SQRT, SUBSTRING, SUM, TABLE, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

CoalesceExpression(AbstractExpression parent)
Creates a new CoalesceExpression.

Method Summary

void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
java.lang.String	encapsulatedExpressionBNF() Returns the BNF used to parse the encapsulated expression.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
protected java.lang.String	parseIdentifier(WordParser wordParser) Parses the identifier of this expression.

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractSingleEncapsulatedExpression

acceptChildren, addChildrenTo, addOrderedEncapsulatedExpressionTo, findQueryBNF, getExpression, hasEncapsulatedExpression, hasExpression, parseEncapsulatedExpression, removeEncapsulatedExpression, setExpression, toParsedTextEncapsulatedExpression

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractEncapsulatedExpression

addOrderedChildrenTo, areLogicalIdentifiersSupported, getActualIdentifier, getIdentifier, hasLeftParenthesis, hasRightParenthesis, hasSpaceAfterIdentifier, isParsingComplete, parse, shouldParseRightParenthesis, toParsedText

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

acceptUnknownVisitor, acceptUnknownVisitor, buildExpressionFromFallingBack, buildNullExpression, buildStringExpression, buildStringExpression, buildUnknownExpression, calculatePosition, children, findFallBackExpressionFactory, getExpressionFactory, getExpressionRegistry, getGrammar, getIdentifierVersion, getJPAVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, getText, handleAggregate, handleCollection, isAncestor, isIdentifier, isNull, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, 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

Constructor Detail

CoalesceExpression

public CoalesceExpression(AbstractExpression parent)

Creates a new CoalesceExpression.

Parameters:

parent - The parent of this expression

Method Detail

accept

public void accept(ExpressionVisitor visitor)

Visits this Expression by the given visitor.

Parameters:

visitor - The ExpressionVisitor to visit this object

encapsulatedExpressionBNF

public java.lang.String encapsulatedExpressionBNF()

Returns the BNF used to parse the encapsulated expression.

Specified by:

encapsulatedExpressionBNF in class AbstractSingleEncapsulatedExpression

Returns:

The BNF used to parse the encapsulated expression

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

parseIdentifier

protected java.lang.String parseIdentifier(WordParser wordParser)

Parses the identifier of this expression.

Specified by:

parseIdentifier in class AbstractEncapsulatedExpression

Returns:

The identifier for this expression