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java.lang.Objectorg.eclipse.persistence.jpa.jpql.parser.AbstractExpression
org.eclipse.persistence.jpa.jpql.parser.IdentificationVariable
public final class IdentificationVariable
An identification variable is a valid identifier declared in the FROM clause of a query.
Requirements:
An identification variable can range over an entity, embeddable, or basic abstract schema type. An identification variable designates an instance of an abstract schema type or an element of a collection of abstract schema type instances.
Note that for identification variables referring to an instance of an association or collection
represented as a Map
, the identification variable is of the abstract schema
type of the map value.
An identification variable always designates a reference to a single value. It is declared in one of three ways:
All identification variables used in the SELECT, WHERE, ORDER BY, GROUP BY, or HAVING clause of a SELECT or DELETE statement must be declared in the FROM clause. The identification variables used in the WHERE clause of an UPDATE statement must be declared in the UPDATE clause.
An identification variable is scoped to the query (or subquery) in which it is defined and is also visible to any subqueries within that query scope that do not define an identification variable of the same name.
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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IdentificationVariable(AbstractExpression parent,
java.lang.String identificationVariable)
Creates a new IdentificationVariable . |
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IdentificationVariable(AbstractExpression parent,
java.lang.String identificationVariable,
boolean virtual)
Creates a new IdentificationVariable . |
Method Summary | |
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void |
accept(ExpressionVisitor visitor)
Visits this Expression by the given visitor . |
void |
acceptChildren(ExpressionVisitor visitor)
Visits the children of this Expression . |
protected void |
addOrderedChildrenTo(java.util.List<Expression> children)
Adds the children of this AbstractExpression to the given list. |
JPQLQueryBNF |
getQueryBNF()
Returns the BNF of this Expression . |
StateFieldPathExpression |
getStateFieldPathExpression()
Returns the actual representation of the parsed information. |
java.lang.String |
getText()
Returns the encapsulated text of this AbstractExpression , which can be used in various
ways, it can be a keyword, a literal, etc. |
java.lang.String |
getVariableName()
Returns the identification variable, which has been changed to be upper case. |
boolean |
isVirtual()
Determines whether this AbstractExpression is virtual, meaning it's not part of the
query but is required for proper navigability. |
protected void |
parse(WordParser wordParser,
boolean tolerant)
Parses the query by starting at the current position, which is part of the given WordParser . |
void |
setVirtualIdentificationVariable(java.lang.String variableName)
Sets a virtual identification variable because the abstract schema name was parsed without one. |
java.lang.String |
toParsedText()
Returns a string representation of this Expression and its children. |
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 |
Constructor Detail |
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public IdentificationVariable(AbstractExpression parent, java.lang.String identificationVariable)
IdentificationVariable
.
parent
- The parent of this expressionidentificationVariable
- The actual identification variablepublic IdentificationVariable(AbstractExpression parent, java.lang.String identificationVariable, boolean virtual)
IdentificationVariable
.
parent
- The parent of this expressionidentificationVariable
- The actual identification variablevirtual
- Determines whether this identification variable is virtual, meaning it's not
part of the query but is required for proper navigabilityMethod Detail |
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public void accept(ExpressionVisitor visitor)
Expression
by the given visitor
.
visitor
- The ExpressionVisitor
to visit this objectpublic 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 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 JPQLQueryBNF getQueryBNF()
Expression
.
JPQLQueryBNF
, which represents the grammar of this Expression
public StateFieldPathExpression getStateFieldPathExpression()
isVirtual()
returns true
. This is valid in an UPDATE and
DELETE queries where the identification variable is not specified.
java.lang.IllegalAccessError
- If this expression does not have a virtual identification variablepublic java.lang.String getText()
AbstractExpression
, which can be used in various
ways, it can be a keyword, a literal, etc.
getText
in class AbstractExpression
public java.lang.String getVariableName()
public boolean isVirtual()
AbstractExpression
is virtual, meaning it's not part of the
query but is required for proper navigability.
isVirtual
in class AbstractExpression
true
if this AbstractExpression
was virtually created to fully
qualify path expression; false
if it was parsedprotected 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 void setVirtualIdentificationVariable(java.lang.String variableName)
variableName
- The identification variable that was generated to identify the "root" objectpublic java.lang.String toParsedText()
Expression
and its children. The expression
should contain whitespace even if the beautified version would not have any. For instance,
"SELECT e " should be returned where Expression.toParsedText()
would return "SELECT e".
toParsedText
in interface Expression
toParsedText
in class AbstractExpression
Expression
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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