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

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.AbstractSelectClause

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.

Since:

2.3

Version:

2.3

Author:

Pascal Filion

See Also:

SelectClause, SimpleSelectClause

Field Summary

private boolean	hasDistinct Determines whether the identifier DISTINCT was parsed.
private boolean	hasSpaceAfterDistinct Determines whether a whitespace was parsed after the DISTINCT.
private boolean	hasSpaceAfterSelect Determines whether a whitespace was parsed after the SELECT.
private AbstractExpression	selectExpression The actual expression of this select clause.

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

AbstractSelectClause(AbstractExpression parent)
Creates a new SelectClause.

Method Summary

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.
Expression	getSelectExpression() Returns the Expression representing the select items.
boolean	hasDistinct() Determines whether the identifier DISTINCT was parsed or not.
boolean	hasSelectExpression() Determines whether the list of select items was parsed.
boolean	hasSpaceAfterDistinct() Determines whether a whitespace was parsed after DISTINCT.
boolean	hasSpaceAfterSelect() Determines whether a whitespace was parsed after SELECT.
(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) abstract JPQLQueryBNF	selectItemBNF() Returns the BNF for the list of select items to parse.
(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, getQueryBNF, 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

Methods inherited from interface org.eclipse.persistence.jpa.internal.jpql.parser.Expression

accept

Field Detail

hasDistinct

private boolean hasDistinct

Determines whether the identifier DISTINCT was parsed.

hasSpaceAfterDistinct

private boolean hasSpaceAfterDistinct

Determines whether a whitespace was parsed after the DISTINCT.

hasSpaceAfterSelect

private boolean hasSpaceAfterSelect

Determines whether a whitespace was parsed after the SELECT.

selectExpression

private AbstractExpression selectExpression

The actual expression of this select clause.

Constructor Detail

AbstractSelectClause

AbstractSelectClause(AbstractExpression parent)

Creates a new SelectClause.

Parameters:

parent - The parent of this expression

Method Detail

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

getSelectExpression

public Expression getSelectExpression()

Returns the Expression representing the select items.

Returns:

The expression representing the select items

hasDistinct

public boolean hasDistinct()

Determines whether the identifier DISTINCT was parsed or not.

Returns:

true if the identifier DISTINCT was parsed; false otherwise

hasSelectExpression

public boolean hasSelectExpression()

Determines whether the list of select items was parsed.

Returns:

true the list of select items was parsed; false otherwise

hasSpaceAfterDistinct

public boolean hasSpaceAfterDistinct()

Determines whether a whitespace was parsed after DISTINCT.

Returns:

true if there was a whitespace after DISTINCT; false otherwise

hasSpaceAfterSelect

public boolean hasSpaceAfterSelect()

Determines whether a whitespace was parsed after SELECT.

Returns:

true if there was a whitespace after SELECT; 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

selectItemBNF

abstract JPQLQueryBNF selectItemBNF()

Returns the BNF for the list of select items to parse.

Returns:

The BNF for the list of select items to parse

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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