Class OrderByItem
- java.lang.Object
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- org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
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- org.eclipse.persistence.jpa.jpql.parser.OrderByItem
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- All Implemented Interfaces:
Expression
public final class OrderByItem extends AbstractExpression
An orderby_item must be one of the following:- A
state_field_path_expressionthat evaluates to an orderable state field of an entity or embeddable class abstract schema type designated in the SELECT clause by one of the following:- A general_identification_variable
- A single_valued_object_path_expression
- A
state_field_path_expressionthat evaluates to the same state field of the same entity or embeddable abstract schema type as astate_field_path_expressionin the SELECT clause - A
result_variablethat refers to an orderable item in the SELECT clause for which the sameresult_variablehas been specified. This may be the result of an aggregate_expression, ascalar_expression, or astate_field_path_expressionin the SELECT clause.
The keyword ASC specifies that ascending ordering be used for the associated orderby_item; the keyword DESC specifies that descending ordering be used. Ascending ordering is the default.
The keyword NULLS FIRST specifies that nulls first ordering be used for the associated orderby_item; the keyword NULLS LAST specifies that nulls last ordering be used. Ascending ordering is the default.
JPA 1.0:
BNF:orderby_item ::= state_field_path_expression [ ASC | DESC ]JPA 2.0
BNF:orderby_item ::= state_field_path_expression | result_variable [ ASC | DESC ]EclipseLink 2.4:
BNF:orderby_item ::= state_field_path_expression | result_variable [ ASC | DESC ] [ NULLS FIRST | NULLS LAST ]- Version:
- 2.5
- Author:
- Pascal Filion
- Since:
- 2.3
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Nested Class Summary
Nested Classes Modifier and Type Class Description static classOrderByItem.NullOrderingThis enumeration lists all the possible choices for ordering nulls in an item.static classOrderByItem.OrderingThis enumeration lists all the possible choices for ordering an item.
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Field Summary
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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
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Fields inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression
ABS, ALL, AND, ANY, AS, AS_OF, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, CONNECT_BY, 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, FIRST, 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, LAST, 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, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, ORDER_SIBLINGS_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SCN, SELECT, SET, SIZE, SOME, SQL, SQRT, START_WITH, SUBSTRING, SUM, TABLE, THEN, TIMESTAMP, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE
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Constructor Summary
Constructors Constructor Description OrderByItem(AbstractExpression parent)Creates a newOrderByItem.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidaccept(ExpressionVisitor visitor)Visits thisExpressionby the givenvisitor.voidacceptChildren(ExpressionVisitor visitor)Visits the children of thisExpression.protected voidaddChildrenTo(java.util.Collection<Expression> children)Adds the children of thisAbstractExpressionto the given collection.protected voidaddOrderedChildrenTo(java.util.List<Expression> children)Adds the children of thisAbstractExpressionto the given list.JPQLQueryBNFfindQueryBNF(Expression expression)Retrieves theJPQLQueryBNFthat represents the fragment of thisExpressionthat was used when parsing the givenExpression.java.lang.StringgetActualNullOrdering()Returns the actualnullordering identifier found in the string representation of the JPQL query, which has the actual case that was used.java.lang.StringgetActualOrdering()Returns the actual ordering identifier found in the string representation of the JPQL query, which has the actual case that was used.ExpressiongetExpression()Returns theExpressionthat represents the order by expression.OrderByItem.NullOrderinggetNullOrdering()Returns the enum constant representing the null ordering type.OrderByItem.OrderinggetOrdering()Returns the enum constant representing the ordering type.JPQLQueryBNFgetQueryBNF()Returns the BNF of thisExpression.booleanhasExpression()Determines whether the order by expression was parsed.booleanhasNulls()Determines whether theNULLSidentifier was parsed.booleanhasOrdering()Determines whetherASCorDESCwas parsed.booleanhasSpaceAfterExpression()Determines whether a whitespace was parsed after the order by expression.booleanhasSpaceAfterNulls()Determines whether a whitespace was parsed after theNULLSidentifier.booleanhasSpaceAfterOrdering()Determines whether a whitespace was parsed after the ordering.booleanisAscending()Determines whether the ordering was specified as being ascendant.booleanisDefault()Determines whether the ordering was not specified.booleanisDescending()Determines whether the ordering was specified as being descendant.booleanisNullsFirst()Determines whether the ordering was specified as being nulls first.booleanisNullsLast()Determines whether the ordering was specified as being nulls first.protected booleanisParsingComplete(WordParser wordParser, java.lang.String word, Expression expression)Determines whether the parsing is complete based on what is left in the given text.protected voidparse(WordParser wordParser, boolean tolerant)Parses the query by starting at the current position, which is part of the givenWordParser.protected voidtoParsedText(java.lang.StringBuilder writer, boolean actual)Generates a string representation of thisExpression, including its children, if it has any.-
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
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Constructor Detail
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OrderByItem
public OrderByItem(AbstractExpression parent)
Creates a newOrderByItem.- Parameters:
parent- The parent of this expression
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Method Detail
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accept
public void accept(ExpressionVisitor visitor)
Visits thisExpressionby the givenvisitor.- Parameters:
visitor- TheExpressionVisitorto visit this object
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acceptChildren
public void acceptChildren(ExpressionVisitor visitor)
Visits the children of thisExpression. This method can be used to optimize traversing the children since a new list is not created every timeExpression.children()is called.This does not traverse the
Expressionsub-hierarchy, use a subclass ofAbstractTraverseChildrenVisitorin order to traverse the entire sub-hierarchy.- Parameters:
visitor- Thevisitorto visit the children of this object.
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addChildrenTo
protected void addChildrenTo(java.util.Collection<Expression> children)
Adds the children of thisAbstractExpressionto the given collection.- Overrides:
addChildrenToin classAbstractExpression- Parameters:
children- The collection used to store the children
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addOrderedChildrenTo
protected void addOrderedChildrenTo(java.util.List<Expression> children)
Adds the children of thisAbstractExpressionto the given list.- Overrides:
addOrderedChildrenToin classAbstractExpression- Parameters:
children- The list used to store the string representation of thisAbstractExpression
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findQueryBNF
public JPQLQueryBNF findQueryBNF(Expression expression)
Retrieves theJPQLQueryBNFthat represents the fragment of thisExpressionthat was used when parsing the givenExpression.- Specified by:
findQueryBNFin interfaceExpression- Overrides:
findQueryBNFin classAbstractExpression- Parameters:
expression- TheExpressionthat is a descendant of this one- Returns:
- The
JPQLQueryBNFthat was used to parse the given expression
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getActualNullOrdering
public java.lang.String getActualNullOrdering()
Returns the actualnullordering identifier found in the string representation of the JPQL query, which has the actual case that was used.- Returns:
- The
nullordering identifier that was actually parsed, if one was present, otherwise an empty string is returned
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getActualOrdering
public java.lang.String getActualOrdering()
Returns the actual ordering identifier found in the string representation of the JPQL query, which has the actual case that was used.- Returns:
- The ordering identifier that was actually parsed, if one was present, otherwise an empty string is returned
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getExpression
public Expression getExpression()
Returns theExpressionthat represents the order by expression.- Returns:
- The expression that was parsed representing the order by expression
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getNullOrdering
public OrderByItem.NullOrdering getNullOrdering()
Returns the enum constant representing the null ordering type.- Returns:
- The constant representing the null ordering, in the case the ordering was not parsed,
then
OrderByItem.NullOrdering.DEFAULTis returned
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getOrdering
public OrderByItem.Ordering getOrdering()
Returns the enum constant representing the ordering type.- Returns:
- The constant representing the ordering, in the case the ordering was not parsed, then
OrderByItem.Ordering.DEFAULTis returned
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getQueryBNF
public JPQLQueryBNF getQueryBNF()
Returns the BNF of thisExpression.- Returns:
- The
JPQLQueryBNF, which represents the grammar of thisExpression
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hasExpression
public boolean hasExpression()
Determines whether the order by expression was parsed.- Returns:
trueif the order by expression was parsed;falseotherwise
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hasNulls
public boolean hasNulls()
Determines whether theNULLSidentifier was parsed.- Returns:
trueif theNULLSidentifier was parsed;falseotherwise
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hasOrdering
public boolean hasOrdering()
Determines whetherASCorDESCwas parsed.- Returns:
trueif the ordering status was parsed;falseotherwise- Since:
- 2.5
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hasSpaceAfterExpression
public boolean hasSpaceAfterExpression()
Determines whether a whitespace was parsed after the order by expression.- Returns:
trueif there was a whitespace after the order by expression;falseotherwise
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hasSpaceAfterNulls
public boolean hasSpaceAfterNulls()
Determines whether a whitespace was parsed after theNULLSidentifier. If the composite identifier was fully parsed -NULLS FIRSTorNULLS LAST- then this is alwaystrue, but if onlyNULLSwas parsed, then this can be useful to determine if there was a space after.- Returns:
trueif there was a whitespace after theNULLSidentifier;falseotherwise
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hasSpaceAfterOrdering
public boolean hasSpaceAfterOrdering()
Determines whether a whitespace was parsed after the ordering.- Returns:
trueif there was a whitespace after the ordering;falseotherwise
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isAscending
public boolean isAscending()
Determines whether the ordering was specified as being ascendant.- Returns:
trueif ASC was parsed;falseotherwise
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isDefault
public boolean isDefault()
Determines whether the ordering was not specified.- Returns:
trueif no ordering was parsed;falseotherwise
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isDescending
public boolean isDescending()
Determines whether the ordering was specified as being descendant.- Returns:
trueif DESC was parsed;falseotherwise
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isNullsFirst
public boolean isNullsFirst()
Determines whether the ordering was specified as being nulls first.- Returns:
trueif NULLS FIRST was parsed;falseotherwise
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isNullsLast
public boolean isNullsLast()
Determines whether the ordering was specified as being nulls first.- Returns:
trueif NULLS LAST was parsed;falseotherwise
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isParsingComplete
protected 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:
isParsingCompletein classAbstractExpression- Parameters:
wordParser- The text to parse based on the current position of the cursorword- The word that was retrieved from the given text, which is the first word in the textexpression- TheExpressionthat has already been parsed- Returns:
trueif the text no longer can't be parsed by the current expression;falseif more can be parsed
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parse
protected void parse(WordParser wordParser, boolean tolerant)
Parses the query by starting at the current position, which is part of the givenWordParser.- Specified by:
parsein classAbstractExpression- Parameters:
wordParser- The text to parse based on the current position of the cursortolerant- Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries
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toParsedText
protected void toParsedText(java.lang.StringBuilder writer, boolean actual)Generates a string representation of thisExpression, including its children, if it has any.- Specified by:
toParsedTextin classAbstractExpression- Parameters:
writer- The buffer used to append thisExpression's string representationactual- Determines whether the string representation should represent what was parsed, i.e. include any "virtual" whitespace (such as ending whitespace) and the actual case of the JPQL identifiers
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