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 }*

Version:

2.5

Author:

Pascal Filion

Since:

2.3

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.
protected void	addChildrenTo(java.util.Collection<Expression> children) Adds the children of this AbstractExpression to the given collection.
protected void	addOrderedChildrenTo(java.util.List<Expression> children) Adds the children of this AbstractExpression to the given list.
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.
protected boolean	isParsingComplete(WordParser wordParser, java.lang.String word, Expression expression) Determines whether the parsing is complete based on what is left in the given text.
protected void	parse(WordParser wordParser, boolean tolerant) Parses the query by starting at the current position, which is part of the given WordParser.
protected boolean	shouldParseWithFactoryFirst() Determines whether the parsing of the query should be performed using the factories first or it should automatically fallback to the fallback factory.
protected void	toParsedText(java.lang.StringBuilder writer, boolean actual) Generates a string representation of this Expression, 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, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, rebuildActualText, rebuildParsedText, setParent, setText, shouldSkipLiteral, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, 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.

addChildrenTo

protected void addChildrenTo(java.util.Collection<Expression> children)

Adds the children of this AbstractExpression to the given collection.

Overrides:

addChildrenTo in class AbstractExpression

Parameters:

children - The collection used to store the children

addOrderedChildrenTo

protected void addOrderedChildrenTo(java.util.List<Expression> children)

Adds the children of this AbstractExpression to the given list.

Overrides:

addOrderedChildrenTo in class AbstractExpression

Parameters:

children - The list used to store the string representation of this AbstractExpression

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

isParsingComplete

protected boolean isParsingComplete(WordParser wordParser,
                                    java.lang.String word,
                                    Expression expression)

Determines whether the parsing is complete based on what is left in the given text. The text is never empty.

Overrides:

isParsingComplete in class AbstractExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

word - The word that was retrieved from the given text, which is the first word in the text

expression - The Expression that has already been parsed

Returns:

true if the text no longer can't be parsed by the current expression; false if more can be parsed

parse

protected 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

shouldParseWithFactoryFirst

protected boolean shouldParseWithFactoryFirst()

Determines whether the parsing of the query should be performed using the factories first or it should automatically fallback to the fallback factory.

Overrides:

shouldParseWithFactoryFirst in class AbstractExpression

Returns:

true is returned by default so the factories are used before falling back

toParsedText

protected void toParsedText(java.lang.StringBuilder writer,
                            boolean actual)

Generates a string representation of this Expression, including its children, if it has any.

Specified by:

toParsedText in class AbstractExpression

Parameters:

writer - The buffer used to append this Expression's string representation

actual - 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