Class AbstractSelectClause
- java.lang.Object
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- org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
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- org.eclipse.persistence.jpa.jpql.parser.AbstractSelectClause
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- All Implemented Interfaces:
Expression
- Direct Known Subclasses:
SelectClause,SimpleSelectClause
public abstract class AbstractSelectClause extends AbstractExpression
The SELECT clause denotes the query result. More than one value may be returned from the SELECT clause of a query. The SELECT clause may contain one or more of the following elements: a single range variable or identification variable that ranges over an entity abstract schema type, a single-valued path expression, an aggregate select expression, a constructor expression.The DISTINCT keyword is used to specify that duplicate values must be eliminated from the query result. If DISTINCT is not specified, duplicate values are not eliminated. Stand-alone identification variables in the SELECT clause may optionally be qualified by the OBJECT operator. The SELECT clause must not use the OBJECT operator to qualify path expressions.
- Version:
- 2.5
- See Also:
SelectClause,SimpleSelectClause- Author:
- Pascal Filion
- Since:
- 2.3
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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 Modifier Constructor Description protectedAbstractSelectClause(AbstractExpression parent)Creates a newSelectClause.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description 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.CollectionExpressionbuildCollectionExpression()Creates a newCollectionExpressionthat will wrap the single select item.JPQLQueryBNFfindQueryBNF(Expression expression)Retrieves theJPQLQueryBNFthat represents the fragment of thisExpressionthat was used when parsing the givenExpression.java.lang.StringgetActualDistinctIdentifier()Returns the actual DISTINCT identifier found in the string representation of the JPQL query, which has the actual case that was used.java.lang.StringgetActualIdentifier()Returns the actual SELECT identifier found in the string representation of the JPQL query, which has the actual case that was used.ExpressiongetSelectExpression()Returns theExpressionrepresenting the select items.abstract java.lang.StringgetSelectItemQueryBNFId()Returns the unique identifier of theJPQLQueryBNFfor the list of select items to parse.booleanhasDistinct()Determines whether the identifier DISTINCT was parsed or not.booleanhasSelectExpression()Determines whether the list of select items was parsed.booleanhasSpaceAfterDistinct()Determines whether a whitespace was parsed after DISTINCT.booleanhasSpaceAfterSelect()Determines whether a whitespace was parsed after SELECT.protected voidparse(WordParser wordParser, boolean tolerant)Parses the query by starting at the current position, which is part of the givenWordParser.protected booleanshouldSkipLiteral(AbstractExpression expression)When parsing an invalid or incomplete query, it is possible two literals would be parsed but in some cases, a CollectionExpression should not be created and the parsing should actually stop here.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, isParsingComplete, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, rebuildActualText, rebuildParsedText, setParent, setText, shouldParseWithFactoryFirst, toActualText, toParsedText, toString
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression
accept, getQueryBNF
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Constructor Detail
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AbstractSelectClause
protected AbstractSelectClause(AbstractExpression parent)
Creates a newSelectClause.- Parameters:
parent- The parent of this expression
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Method Detail
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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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buildCollectionExpression
public CollectionExpression buildCollectionExpression()
Creates a newCollectionExpressionthat will wrap the single select item.- Returns:
- The single select item represented by a temporary collection
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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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getActualDistinctIdentifier
public final java.lang.String getActualDistinctIdentifier()
Returns the actual DISTINCT identifier found in the string representation of the JPQL query, which has the actual case that was used.- Returns:
- The DISTINCT identifier that was actually parsed, or an empty string if it was not parsed
- Since:
- 2.4
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getActualIdentifier
public final java.lang.String getActualIdentifier()
Returns the actual SELECT identifier found in the string representation of the JPQL query, which has the actual case that was used.- Returns:
- The SELECT identifier that was actually parsed
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getSelectExpression
public final Expression getSelectExpression()
Returns theExpressionrepresenting the select items.- Returns:
- The expression representing the select items
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getSelectItemQueryBNFId
public abstract java.lang.String getSelectItemQueryBNFId()
Returns the unique identifier of theJPQLQueryBNFfor the list of select items to parse.- Returns:
- The ID of the query BNF for the list of select items to parse
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hasDistinct
public final boolean hasDistinct()
Determines whether the identifier DISTINCT was parsed or not.- Returns:
trueif the identifier DISTINCT was parsed;falseotherwise
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hasSelectExpression
public final boolean hasSelectExpression()
Determines whether the list of select items was parsed.- Returns:
truethe list of select items was parsed;falseotherwise
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hasSpaceAfterDistinct
public final boolean hasSpaceAfterDistinct()
Determines whether a whitespace was parsed after DISTINCT.- Returns:
trueif there was a whitespace after DISTINCT;falseotherwise
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hasSpaceAfterSelect
public final boolean hasSpaceAfterSelect()
Determines whether a whitespace was parsed after SELECT.- Returns:
trueif there was a whitespace after SELECT;falseotherwise
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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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shouldSkipLiteral
protected boolean shouldSkipLiteral(AbstractExpression expression)
When parsing an invalid or incomplete query, it is possible two literals would be parsed but in some cases, a CollectionExpression should not be created and the parsing should actually stop here. Example: BETWEEN 10 20, when parsing 20, it should not be parsed as part of the lower bound expression.- Overrides:
shouldSkipLiteralin classAbstractExpression- Parameters:
expression- TheExpressionthat has just been parsed ornull- Returns:
true
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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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