Class AbstractSelectClause

  • All Implemented Interfaces:
    Direct Known Subclasses:
    SelectClause, SimpleSelectClause

    public abstract class AbstractSelectClause
    extends AbstractExpression
    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.

    See Also:
    SelectClause, SimpleSelectClause
    Pascal Filion
    • Constructor Detail

      • AbstractSelectClause

        protected AbstractSelectClause​(AbstractExpression parent)
        Creates a new SelectClause.
        parent - The parent of this expression
    • Method Detail

      • buildCollectionExpression

        public CollectionExpression buildCollectionExpression()
        Creates a new CollectionExpression that will wrap the single select item.
        The single select item represented by a temporary collection
      • getActualDistinctIdentifier

        public final 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.
        The DISTINCT identifier that was actually parsed, or an empty string if it was not parsed
      • getActualIdentifier

        public final 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.
        The SELECT identifier that was actually parsed
      • getSelectExpression

        public final Expression getSelectExpression()
        Returns the Expression representing the select items.
        The expression representing the select items
      • getSelectItemQueryBNFId

        public abstract java.lang.String getSelectItemQueryBNFId()
        Returns the unique identifier of the JPQLQueryBNF for the list of select items to parse.
        The ID of the query BNF for the list of select items to parse
      • hasDistinct

        public final boolean hasDistinct()
        Determines whether the identifier DISTINCT was parsed or not.
        true if the identifier DISTINCT was parsed; false otherwise
      • hasSelectExpression

        public final boolean hasSelectExpression()
        Determines whether the list of select items was parsed.
        true the list of select items was parsed; false otherwise
      • hasSpaceAfterDistinct

        public final boolean hasSpaceAfterDistinct()
        Determines whether a whitespace was parsed after DISTINCT.
        true if there was a whitespace after DISTINCT; false otherwise
      • hasSpaceAfterSelect

        public final boolean hasSpaceAfterSelect()
        Determines whether a whitespace was parsed after SELECT.
        true if there was a whitespace after SELECT; false otherwise
      • 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
        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
      • shouldSkipLiteral

        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. Example: BETWEEN 10 20, when parsing 20, it should not be parsed as part of the lower bound expression.
        shouldSkipLiteral in class AbstractExpression
        expression - The Expression that has just been parsed or null
      • 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
        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