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

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

Method Summary

Methods

Modifier and Type	Method and Description
void	acceptChildren(ExpressionVisitor visitor) Visits the children of 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.

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

children, findQueryBNF, getChildren, getParent, getQueryBNF, getRoot, identifierRole, identifiers, identifierVersion, isAncestor, isIdentifier, isVirtual, orderedChildren, queryBNF, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

accept

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.

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