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java.lang.Objectorg.eclipse.persistence.jpa.jpql.parser.AbstractExpression
org.eclipse.persistence.jpa.jpql.parser.AbstractSelectClause
public abstract class AbstractSelectClause
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.
SelectClause
,
SimpleSelectClause
Field Summary |
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Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression |
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COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE |
Constructor Summary | |
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protected |
AbstractSelectClause(AbstractExpression parent)
Creates a new SelectClause . |
Method Summary | |
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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 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. |
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. |
protected void |
parse(WordParser wordParser,
boolean tolerant)
Parses the query by starting at the current position, which is part of the given WordParser . |
abstract java.lang.String |
selectItemBNF()
Returns the BNF for the list of select items to parse. |
protected boolean |
shouldSkipLiteral(AbstractExpression expression)
When parsing an invalid or incomplete query, it is possible two literals would be parsed but in some cases, a CollectionExpression should not be created and the parsing should actually stop here. |
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 java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression |
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accept, getQueryBNF |
Constructor Detail |
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protected AbstractSelectClause(AbstractExpression parent)
SelectClause
.
parent
- The parent of this expressionMethod Detail |
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public void acceptChildren(ExpressionVisitor visitor)
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.
visitor
- The visitor
to visit the children of this object.protected void addChildrenTo(java.util.Collection<Expression> children)
AbstractExpression
to the given collection.
addChildrenTo
in class AbstractExpression
children
- The collection used to store the childrenprotected void addOrderedChildrenTo(java.util.List<Expression> children)
AbstractExpression
to the given list.
addOrderedChildrenTo
in class AbstractExpression
children
- The list used to store the string representation of this AbstractExpression
public CollectionExpression buildCollectionExpression()
CollectionExpression
that will wrap the single select item.
public JPQLQueryBNF findQueryBNF(Expression expression)
JPQLQueryBNF
that represents the fragment of this Expression
that was used when parsing the given Expression
.
findQueryBNF
in interface Expression
findQueryBNF
in class AbstractExpression
expression
- The Expression
that is a descendant of this one
JPQLQueryBNF
that was used to parse the given expressionpublic final java.lang.String getActualDistinctIdentifier()
public final java.lang.String getActualIdentifier()
public final Expression getSelectExpression()
Expression
representing the select items.
public final boolean hasDistinct()
true
if the identifier DISTINCT was parsed;
false
otherwisepublic final boolean hasSelectExpression()
true
the list of select items was parsed;
false
otherwisepublic final boolean hasSpaceAfterDistinct()
true
if there was a whitespace after DISTINCT;
false
otherwisepublic final boolean hasSpaceAfterSelect()
true
if there was a whitespace after SELECT;
false
otherwiseprotected void parse(WordParser wordParser, boolean tolerant)
WordParser
.
parse
in class AbstractExpression
wordParser
- The text to parse based on the current position of the cursortolerant
- Determines whether the parsing system should be tolerant, meaning if it should
try to parse invalid or incomplete queriespublic abstract java.lang.String selectItemBNF()
protected boolean shouldSkipLiteral(AbstractExpression expression)
shouldSkipLiteral
in class AbstractExpression
expression
- The Expression
that has just been parsed or null
true
protected void toParsedText(java.lang.StringBuilder writer, boolean actual)
Expression
, including its children,
if it has any.
toParsedText
in class AbstractExpression
writer
- The buffer used to append this Expression
's string representationactual
- 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
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EclipseLink 2.4.2, build 'v20130514-5956486' API Reference | ||||||||
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