org.eclipse.persistence.jpa.jpql.parser
Class AbstractFromClause

java.lang.Object
  org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
      org.eclipse.persistence.jpa.jpql.parser.AbstractFromClause

All Implemented Interfaces:

Expression

Direct Known Subclasses:

FromClause, SimpleFromClause

public abstract class AbstractFromClause
extends AbstractExpression

The FROM clause of a query defines the domain of the query by declaring identification variables. An identification variable is an identifier declared in the FROM clause of a query. The domain of the query may be constrained by path expressions. Identification variables designate instances of a particular entity abstract schema type. The FROM clause can contain multiple identification variable declarations separated by a comma (,).

Version:

2.5

See Also:

FromClause, SimpleFromClause

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

protected

AbstractFromClause(AbstractExpression parent) Creates a new AbstractFromClause.

Method Summary

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 declaration.
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	getActualIdentifier() Returns the actual FROM identifier found in the string representation of the JPQL query, which has the actual case that was used.
Expression	getAsOfClause() Returns the Expression representing the AS OF clause.
Expression	getDeclaration() Returns the Expression that represents the declaration of this clause.
abstract java.lang.String	getDeclarationQueryBNFId() Returns the BNF of the declaration part of this clause.
Expression	getHierarchicalQueryClause() Returns the Expression representing the hierarchical query clause.
boolean	hasAsOfClause() Determines whether the AS OF clause is defined.
boolean	hasDeclaration() Determines whether the declaration of this clause was parsed.
boolean	hasHierarchicalQueryClause() Determines whether the hierarchical query clause was parsed or not.
boolean	hasSpaceAfterDeclaration() Determines whether a whitespace was found after the declaration query clause, which will be true if it's followed by either the hierarchical query clause or the AS OF clause.
boolean	hasSpaceAfterFrom() Determines whether a whitespace was parsed after the FROM identifier.
boolean	hasSpaceAfterHierarchicalQueryClause() Determines whether a whitespace was found after the hierarchical query clause.
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

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

accept, getQueryBNF

Constructor Detail

AbstractFromClause

protected AbstractFromClause(AbstractExpression parent)

Creates a new AbstractFromClause.

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() 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 final CollectionExpression buildCollectionExpression()

Creates a new CollectionExpression that will wrap the single declaration.

Returns:

The single declaration represented by a temporary collection

findQueryBNF

public final 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

getActualIdentifier

public final java.lang.String getActualIdentifier()

Returns the actual FROM identifier found in the string representation of the JPQL query, which has the actual case that was used.

Returns:

The FROM identifier that was actually parsed

getAsOfClause

public final Expression getAsOfClause()

Returns the Expression representing the AS OF clause.

Returns:

The expression representing the AS OF clause

getDeclaration

public final Expression getDeclaration()

Returns the Expression that represents the declaration of this clause.

Returns:

The expression that was parsed representing the declaration

getDeclarationQueryBNFId

public abstract java.lang.String getDeclarationQueryBNFId()

Returns the BNF of the declaration part of this clause.

Returns:

The BNF of the declaration part of this clause

getHierarchicalQueryClause

public final Expression getHierarchicalQueryClause()

Returns the Expression representing the hierarchical query clause.

Returns:

The expression representing the hierarchical query clause

Since:

2.5

hasAsOfClause

public final boolean hasAsOfClause()

Determines whether the AS OF clause is defined.

Returns:

true if the query that got parsed had the AS OF clause

hasDeclaration

public final boolean hasDeclaration()

Determines whether the declaration of this clause was parsed.

Returns:

true if the declaration of this clause was parsed; false if it was not parsed

hasHierarchicalQueryClause

public final boolean hasHierarchicalQueryClause()

Determines whether the hierarchical query clause was parsed or not.

Returns:

true if the query that got parsed had the hierarchical query clause

Since:

2.5

hasSpaceAfterDeclaration

public final boolean hasSpaceAfterDeclaration()

Determines whether a whitespace was found after the declaration query clause, which will be true if it's followed by either the hierarchical query clause or the AS OF clause.

Returns:

true if there was a whitespace after the declaration; false otherwise

Since:

2.5

hasSpaceAfterFrom

public final boolean hasSpaceAfterFrom()

Determines whether a whitespace was parsed after the FROM identifier.

Returns:

true if a whitespace was parsed after the FROM identifier; false otherwise

hasSpaceAfterHierarchicalQueryClause

public final boolean hasSpaceAfterHierarchicalQueryClause()

Determines whether a whitespace was found after the hierarchical query clause. In some cases, the space is owned by a child of the hierarchical query clause.

Returns:

true if there was a whitespace after the hierarchical query clause and owned by this expression; false otherwise

Since:

2.5

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