org.eclipse.persistence.jpa.jpql.parser

Class AbstractSelectClause

java.lang.Object

org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

org.eclipse.persistence.jpa.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:

2.5

Author:

Pascal Filion

See Also:

SelectClause, SimpleSelectClause

Field Summary

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

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

Method Summary

Modifier and Type	Method and Description
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
CollectionExpression	buildCollectionExpression() Creates a new CollectionExpression that will wrap the single select item.
JPQLQueryBNF	findQueryBNF(Expression expression) Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
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.
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.
Expression	getSelectExpression() Returns the Expression representing the select items.
abstract java.lang.String	getSelectItemQueryBNFId() Returns the unique identifier of the JPQLQueryBNF for the list of select items to parse.
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.jpql.parser.AbstractExpression

children, getGrammar, getIdentifierVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, isAncestor, orderedChildren, populatePosition, 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.jpql.parser.Expression

accept, getQueryBNF

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() is called.

This does not traverse the Expression sub-hierarchy, use a subclass of AbstractTraverseChildrenVisitor in order to traverse the entire sub-hierarchy.

Parameters:

visitor - The visitor to visit the children of this object.

buildCollectionExpression

public CollectionExpression buildCollectionExpression()

Creates a new CollectionExpression that will wrap the single select item.

Returns:

The single select item represented by a temporary collection

findQueryBNF

public JPQLQueryBNF findQueryBNF(Expression expression)

Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.

Specified by:

findQueryBNF in interface Expression

Overrides:

findQueryBNF in class AbstractExpression

Parameters:

expression - The Expression that is a descendant of this one

Returns:

The JPQLQueryBNF that was used to parse the given expression

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

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

getSelectExpression

public final Expression getSelectExpression()

Returns the Expression representing the select items.

Returns:

The expression representing the select items

getSelectItemQueryBNFId

public abstract java.lang.String getSelectItemQueryBNFId()

Returns the unique identifier of the JPQLQueryBNF for the list of select items to parse.

Returns:

The ID of the query BNF for the list of select items to parse

hasDistinct

public final boolean hasDistinct()

Determines whether the identifier DISTINCT was parsed or not.

Returns:

true if the identifier DISTINCT was parsed; false otherwise

hasSelectExpression

public final boolean hasSelectExpression()

Determines whether the list of select items was parsed.

Returns:

true the list of select items was parsed; false otherwise

hasSpaceAfterDistinct

public final boolean hasSpaceAfterDistinct()

Determines whether a whitespace was parsed after DISTINCT.

Returns:

true if there was a whitespace after DISTINCT; false otherwise

hasSpaceAfterSelect

public final boolean hasSpaceAfterSelect()

Determines whether a whitespace was parsed after SELECT.

Returns:

true if there was a whitespace after SELECT; false otherwise