Module org.eclipse.persistence.jpa.jpql
Package org.eclipse.persistence.jpa.jpql.parser

Class ResultVariable

java.lang.Object
org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
org.eclipse.persistence.jpa.jpql.parser.ResultVariable
All Implemented Interfaces:
Expression
public final class ResultVariable extends AbstractExpression
A result variable may be used to name a select item in the query result.
BNF: select_item ::= select_expression [[AS] result_variable]
Since:
2.3
Version:
2.5

  • Constructor Details

    • ResultVariable

      public ResultVariable(AbstractExpression parent, AbstractExpression selectExpression)
      Creates a new ResultVariable.
      Parameters:
      parent - The parent of this expression
      selectExpression - The expression that represents the select expression, which will have a variable assigned to it

  • Method Details

    • accept

      public void accept(ExpressionVisitor visitor)
      Description copied from interface: Expression
      Visits this Expression by the given visitor.
      Parameters:
      visitor - The ExpressionVisitor to visit this object

    • acceptChildren

      public void acceptChildren(ExpressionVisitor visitor)
      Description copied from interface: Expression
      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(Collection<Expression> children)
      Description copied from class: AbstractExpression
      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(List<Expression> children)
      Description copied from class: AbstractExpression
      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

    • findQueryBNF

      public JPQLQueryBNF findQueryBNF(Expression expression)
      Description copied from interface: 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

    • getActualAsIdentifier

      public String getActualAsIdentifier()
      Returns the actual AS found in the string representation of the JPQL query, which has the actual case that was used.
      Returns:
      The AS identifier that was actually parsed, or an empty string if it was not parsed

    • getQueryBNF

      public JPQLQueryBNF getQueryBNF()
      Description copied from interface: Expression
      Returns the BNF of this Expression.
      Returns:
      The JPQLQueryBNF, which represents the grammar of this Expression

    • getResultVariable

      public Expression getResultVariable()
      Returns the Expression representing the result variable.
      Returns:
      The expression for the result variable

    • getSelectExpression

      public Expression getSelectExpression()
      Returns the Expression representing the select expression.
      Returns:
      The expression for the select expression

    • hasAs

      public boolean hasAs()
      Determines whether the identifier AS was parsed or not.
      Returns:
      true if the identifier AS was parsed; false otherwise

    • hasResultVariable

      public boolean hasResultVariable()
      Determines whether the result variable was parsed.
      Returns:
      true if the result variable was parsed; false otherwise

    • hasSelectExpression

      public boolean hasSelectExpression()
      Determines whether a select expression was defined for this result variable.
      Returns:
      true if the select expression was parsed; false if the result variable was parsed without one

    • hasSpaceAfterAs

      public boolean hasSpaceAfterAs()
      Determines whether a whitespace was parsed after the identifier AS.
      Returns:
      true if there was a whitespace after AS; false otherwise

    • parse

      protected void parse(WordParser wordParser, boolean tolerant)
      Description copied from class: AbstractExpression
      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

    • toParsedText

      protected void toParsedText(StringBuilder writer, boolean actual)
      Description copied from class: AbstractExpression
      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