org.eclipse.persistence.jpa.jpql.parser

Class IdentificationVariableDeclaration

java.lang.Object

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

org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration

All Implemented Interfaces:

Expression

public final class IdentificationVariableDeclaration
extends AbstractExpression

An identification variable is a valid identifier declared in the FROM clause of a query. All identification variables must be declared in the FROM clause. Identification variables cannot be declared in other clauses. An identification variable must not be a reserved identifier or have the same name as any entity in the same persistence unit: Identification variables are case insensitive. An identification variable evaluates to a value of the type of the expression used in declaring the variable.

BNF: identification_variable_declaration ::= range_variable_declaration { join | fetch_join }*

Since:

2.3

Version:

2.5

Author:

Pascal Filion

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

Constructor Summary

Constructors

Constructor and Description
IdentificationVariableDeclaration(AbstractExpression parent) Creates a new IdentificationVariableDeclaration.

Method Summary

Modifier and Type	Method and Description
void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
CollectionExpression	buildCollectionExpression() Creates a new CollectionExpression that will wrap the single join expression.
JPQLQueryBNF	findQueryBNF(Expression expression) Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
Expression	getJoins() Returns the unique join (fetch join) or the list of joins (fetch joins) expression.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
Expression	getRangeVariableDeclaration() Returns the variable declaration, which is the abstract schema name and the identification variable.
boolean	hasJoins() Determines whether this declaration has any join expressions.
boolean	hasRangeVariableDeclaration() Determines whether the range variable declaration was parsed.
boolean	hasSpace() Determines whether there is a space after the range variable declaration.

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

Constructor Detail

IdentificationVariableDeclaration

public IdentificationVariableDeclaration(AbstractExpression parent)

Creates a new IdentificationVariableDeclaration.

Parameters:

parent - The parent of this expression

Method Detail

accept

public void accept(ExpressionVisitor visitor)

Visits this Expression by the given visitor.

Parameters:

visitor - The ExpressionVisitor to visit this object

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 join expression.

Returns:

The single join expression 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

getJoins

public Expression getJoins()

Returns the unique join (fetch join) or the list of joins (fetch joins) expression.

Returns:

The JOIN expression(s) or a null expression if none was declared

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

getRangeVariableDeclaration

public Expression getRangeVariableDeclaration()

Returns the variable declaration, which is the abstract schema name and the identification variable.

Returns:

The Expression representing the range variable declaration

hasJoins

public boolean hasJoins()

Determines whether this declaration has any join expressions.

Returns:

true if at least one join expression was specified; false otherwise

hasRangeVariableDeclaration

public boolean hasRangeVariableDeclaration()

Determines whether the range variable declaration was parsed.

Returns:

true if the range variable declaration was parsed; false otherwise

hasSpace

public boolean hasSpace()

Determines whether there is a space after the range variable declaration.

Returns:

true if the range variable declaration is followed by a space, false otherwise