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

java.lang.Object
org.eclipse.persistence.jpa.internal.jpql.parser.StringExpression
org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression
org.eclipse.persistence.jpa.internal.jpql.parser.CompoundExpression
org.eclipse.persistence.jpa.internal.jpql.parser.ComparisonExpression

All Implemented Interfaces:

Expression

public final class ComparisonExpression

extends CompoundExpression

Only the values of like types are permitted to be compared. A type is like another type if they correspond to the same Java language type, or if one is a primitive Java language type and the other is the wrapped Java class type equivalent (e.g., int and Integer are like types in this sense).

There is one exception to this rule: it is valid to compare numeric values for which the rules of numeric promotion apply. Conditional expressions attempting to compare non-like type values are disallowed except for this numeric case.

Note that the arithmetic operators and comparison operators are permitted to be applied to state-fields and input parameters of the wrapped Java class equivalents to the primitive numeric Java types. Two entities of the same abstract schema type are equal if and only if they have the same primary key value. Only equality/inequality comparisons over enumeration constants are required to be supported.

JPA 1.0 - BNF:

comparison_expression ::= string_expression comparison_operator {string_expression | all_or_any_expression} |
                          boolean_expression {=|<>} {boolean_expression | all_or_any_expression} |
                          enum_expression {=|<>} {enum_expression | all_or_any_expression} |
                          datetime_expression comparison_operator {datetime_expression | all_or_any_expression} |
                          entity_expression {=|<>} {entity_expression | all_or_any_expression} |
                          arithmetic_expression comparison_operator {arithmetic_expression | all_or_any_expression}

JPA 2.0 - BNF:

comparison_expression ::= string_expression comparison_operator {string_expression | all_or_any_expression} |
                          boolean_expression {=|<>} {boolean_expression | all_or_any_expression} |
                          enum_expression {=|<>} {enum_expression | all_or_any_expression} |
                          datetime_expression comparison_operator {datetime_expression | all_or_any_expression} |
                          entity_expression {=|<>} {entity_expression | all_or_any_expression} |
                          arithmetic_expression comparison_operator {arithmetic_expression | all_or_any_expression} |
                          entity_type_expression {=|<>} entity_type_expression}

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

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

ComparisonExpression(AbstractExpression parent)
Creates a new ComparisonExpression.

Method Summary

void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
java.lang.String	getComparisonOperator() Returns the comparison operator, which is either '=', '>', '>=', '<', '<=' or '<>'.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
(package private) boolean	isParsingComplete(WordParser wordParser, java.lang.String word, Expression expression) Determines whether the parsing is complete based on what is left in the given text.
(package private) java.lang.String	parseIdentifier(WordParser wordParser) Parses the identifier of this expression.
JPQLQueryBNF	rightExpressionBNF() Returns the BNF used to determine how to parse the right expression.

Methods inherited from class org.eclipse.persistence.jpa.internal.jpql.parser.CompoundExpression

acceptChildren, addChildrenTo, addOrderedChildrenTo, getLeftExpression, getRightExpression, hasLeftExpression, hasRightExpression, hasSpaceAfterIdentifier, parse, setLeftExpression, setRightExpression, toParsedText

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, 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

Constructor Detail

ComparisonExpression

ComparisonExpression(AbstractExpression parent)

Creates a new ComparisonExpression.

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 visitor to visit this object

getComparisonOperator

public java.lang.String getComparisonOperator()

Returns the comparison operator, which is either '=', '>', '>=', '<', '<=' or '<>'.

Returns:

The operator comparing the two expressions

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

isParsingComplete

boolean isParsingComplete(WordParser wordParser,
                          java.lang.String word,
                          Expression expression)

Determines whether the parsing is complete based on what is left in the given text. The text is never empty.

Overrides:

isParsingComplete in class AbstractExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

word - The word that was retrieved from the given text, which is the first word in the text

expression - The Expression that has already been parsed

Returns:

true if the text no longer can't be parsed by the current expression; false if more can be parsed

parseIdentifier

java.lang.String parseIdentifier(WordParser wordParser)

Parses the identifier of this expression.

Specified by:

parseIdentifier in class CompoundExpression

Returns:

The identifier for this expression

rightExpressionBNF

public JPQLQueryBNF rightExpressionBNF()

Returns the BNF used to determine how to parse the right expression.

Specified by:

rightExpressionBNF in class CompoundExpression

Returns:

The BNF used when parsing the expression after the identifier

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