Class UnaryOperatorNode

    • Field Detail

      • operator

        java.lang.String operator
      • methodName

        java.lang.String methodName
      • resultInterfaceType

        java.lang.String resultInterfaceType
      • receiverInterfaceType

        java.lang.String receiverInterfaceType
      • operand

        ValueNode operand
        WARNING: operand may be NULL for COUNT(*).
      • UnaryOperators

        static final java.lang.String[] UnaryOperators
      • UnaryMethodNames

        static final java.lang.String[] UnaryMethodNames
      • UnaryResultTypes

        static final java.lang.String[] UnaryResultTypes
      • UnaryArgTypes

        static final java.lang.String[] UnaryArgTypes
      • targetType

        private DataTypeDescriptor targetType
        Target type for XMLSerialize operator.
      • preserveWhitespace

        private boolean preserveWhitespace
        Whether or not an XMLParse operator should preserve whitespace.
    • Constructor Detail

      • UnaryOperatorNode

        UnaryOperatorNode​(ValueNode operand,
                          ContextManager cm)
        When UnaryOperatorNode is used as an base class, this constructor is used as super.
      • UnaryOperatorNode

        UnaryOperatorNode​(ValueNode operand,
                          int kind,
                          DataTypeDescriptor targetType,
                          boolean preserveWhiteSpace,
                          ContextManager cm)
        Constructor for a UnaryOperatorNode when used as a concrete class.
        Parameters:
        operand - The operand of the node
        kind - The kind of operator
        targetType - The DTD of the target type
        preserveWhiteSpace - true if white space is to be preserved (relevant for kind == XMLPARSE only)
        cm - The context manager
    • Method Detail

      • setOperator

        void setOperator​(java.lang.String operator)
        Set the operator.
        Parameters:
        operator - The operator.
      • getOperatorString

        java.lang.String getOperatorString()
        Get the operator of this unary operator.
        Returns:
        The operator of this unary operator.
      • setMethodName

        void setMethodName​(java.lang.String methodName)
        Set the methodName.
        Parameters:
        methodName - The methodName.
      • toString

        public java.lang.String toString()
        Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.
        Overrides:
        toString in class ValueNode
        Returns:
        This object as a String
      • printSubNodes

        void printSubNodes​(int depth)
        Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.
        Overrides:
        printSubNodes in class QueryTreeNode
        Parameters:
        depth - The depth of this node in the tree
      • getOperand

        ValueNode getOperand()
        Get the operand of this unary operator.
        Returns:
        The operand of this unary operator.
      • getParameterOperand

        ParameterNode getParameterOperand()
                                   throws StandardException
        Get the parameter operand of this unary operator. For the example below, for abs unary operator node, we want to get ? select * from t1 where -? = max_cni(abs(-?), sqrt(+?)) This gets called when ParameterNode is needed to get parameter specific information like getDefaultValue(), getParameterNumber() etc
        Returns:
        The parameter operand of this unary operator else null.
        Throws:
        StandardException
      • bindExpression

        ValueNode bindExpression​(FromList fromList,
                                 SubqueryList subqueryList,
                                 java.util.List<AggregateNode> aggregates)
                          throws StandardException
        Bind this expression. This means binding the sub-expressions, as well as figuring out what the return type is for this expression. This method is the implementation for XMLPARSE and XMLSERIALIZE. Sub-classes need to implement their own bindExpression() method for their own specific rules.
        Overrides:
        bindExpression in class ValueNode
        Parameters:
        fromList - The FROM list for the query this expression is in, for binding columns.
        subqueryList - The subquery list being built as we find SubqueryNodes
        aggregates - The aggregate list being built as we find AggregateNodes
        Returns:
        The new top of the expression tree.
        Throws:
        StandardException - Thrown on error
      • bindOperand

        protected void bindOperand​(FromList fromList,
                                   SubqueryList subqueryList,
                                   java.util.List<AggregateNode> aggregates)
                            throws StandardException
        Bind the operand for this unary operator. Binding the operator may change the operand node. Sub-classes bindExpression() methods need to call this method to bind the operand.
        Throws:
        StandardException
      • bindXMLParse

        private void bindXMLParse()
                           throws StandardException
        Bind an XMLPARSE operator. Makes sure the operand type is correct, and sets the result type.
        Throws:
        StandardException - Thrown on error
      • bindXMLSerialize

        private void bindXMLSerialize()
                               throws StandardException
        Bind an XMLSERIALIZE operator. Makes sure the operand type and target type are both correct, and sets the result type.
        Throws:
        StandardException - Thrown on error
      • preprocess

        ValueNode preprocess​(int numTables,
                             FromList outerFromList,
                             SubqueryList outerSubqueryList,
                             PredicateList outerPredicateList)
                      throws StandardException
        Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening. NOTE: This is done before the outer ResultSetNode is preprocessed.
        Overrides:
        preprocess in class ValueNode
        Parameters:
        numTables - Number of tables in the DML Statement
        outerFromList - FromList from outer query block
        outerSubqueryList - SubqueryList from outer query block
        outerPredicateList - PredicateList from outer query block
        Returns:
        The modified expression
        Throws:
        StandardException - Thrown on error
      • categorize

        boolean categorize​(JBitSet referencedTabs,
                           boolean simplePredsOnly)
                    throws StandardException
        Categorize this predicate. Initially, this means building a bit map of the referenced tables for each predicate. If the source of this ColumnReference (at the next underlying level) is not a ColumnReference or a VirtualColumnNode then this predicate will not be pushed down. For example, in: select * from (select 1 from s) a (x) where x = 1 we will not push down x = 1. NOTE: It would be easy to handle the case of a constant, but if the inner SELECT returns an arbitrary expression, then we would have to copy that tree into the pushed predicate, and that tree could contain subqueries and method calls. RESOLVE - revisit this issue once we have views.
        Overrides:
        categorize in class ValueNode
        Parameters:
        referencedTabs - JBitSet with bit map of referenced FromTables
        simplePredsOnly - Whether or not to consider method calls, field references and conditional nodes when building bit map
        Returns:
        boolean Whether or not source.expression is a ColumnReference or a VirtualColumnNode.
        Throws:
        StandardException - Thrown on error
      • isConstantExpression

        boolean isConstantExpression()
        Return whether or not this expression tree represents a constant expression.
        Overrides:
        isConstantExpression in class ValueNode
        Returns:
        Whether or not this expression tree represents a constant expression.
      • bindParameter

        void bindParameter()
                    throws StandardException
        By default unary operators don't accept ? parameters as operands. This can be over-ridden for particular unary operators. We throw an exception if the parameter doesn't have a datatype assigned to it yet.
        Throws:
        StandardException - Thrown if ? parameter doesn't have a type bound to it yet. ? parameter where it isn't allowed.
      • getReceiverInterfaceName

        java.lang.String getReceiverInterfaceName()
                                           throws StandardException
        Determine the type the binary method is called on. By default, based on the receiver. Override in nodes that use methods on super-interfaces of the receiver's interface, such as comparisons.
        Throws:
        StandardException - Thrown on error
      • getOrderableVariantType

        protected int getOrderableVariantType()
                                       throws StandardException
        Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions) CONSTANT - immutable
        Overrides:
        getOrderableVariantType in class ValueNode
        Returns:
        The variant type for the underlying expression.
        Throws:
        StandardException - thrown on error
      • addXmlOpMethodParams

        int addXmlOpMethodParams​(ExpressionClassBuilder acb,
                                 MethodBuilder mb,
                                 LocalField resultField)
                          throws StandardException
        Add some additional arguments to our method call for XML related operations like XMLPARSE and XMLSERIALIZE.
        Parameters:
        acb - the builder for the class in which the method lives
        mb - The MethodBuilder that will make the call.
        resultField - the field that contains the previous result
        Returns:
        Number of parameters added.
        Throws:
        StandardException
      • isEquivalent

        boolean isEquivalent​(ValueNode o)
                      throws StandardException
        Description copied from class: ValueNode
        Tests if this node is equivalent to the specified ValueNode. Two ValueNodes are considered equivalent if they will evaluate to the same value during query execution.

        This method provides basic expression matching facility for the derived class of ValueNode and it is used by the language layer to compare the node structural form of the two expressions for equivalence at bind phase.

        Note that it is not comparing the actual row values at runtime to produce a result; hence, when comparing SQL NULLs, they are considered to be equivalent and not unknown.

        One usage case of this method in this context is to compare the select column expression against the group by expression to check if they are equivalent. e.g.:

        SELECT c1+c2 FROM t1 GROUP BY c1+c2

        In general, node equivalence is determined by the derived class of ValueNode. But they generally abide to the rules below:

        • The two ValueNodes must be of the same node type to be considered equivalent. e.g.: CastNode vs. CastNode - equivalent (if their args also match), ColumnReference vs CastNode - not equivalent.
        • If node P contains other ValueNode(s) and so on, those node(s) must also be of the same node type to be considered equivalent.
        • If node P takes a parameter list, then the number of arguments and its arguments for the two nodes must also match to be considered equivalent. e.g.: CAST(c1 as INTEGER) vs CAST(c1 as SMALLINT), they are not equivalent.
        • When comparing SQL NULLs in this context, they are considered to be equivalent.
        • If this does not apply or it is determined that the two nodes are not equivalent then the derived class of this method should return false; otherwise, return true.
        Specified by:
        isEquivalent in class ValueNode
        Parameters:
        o - the node to compare this ValueNode against.
        Returns:
        true if the two nodes are equivalent, false otherwise.
        Throws:
        StandardException
      • isSameNodeKind

        boolean isSameNodeKind​(ValueNode o)
        Description copied from class: ValueNode
        Some node classes represent several logical node types (to reduce footprint), which we call kinds. This means that implementations of ValueNode.isEquivalent(org.apache.derby.impl.sql.compile.ValueNode) cannot always just use instanceof to check if the other node represents the same kind. Hence this method needs to be overridden by all node classes that represent several kinds. This default implementation does not look at kinds. It is only called from implementations of isEquivalent.
        Overrides:
        isSameNodeKind in class ValueNode
        Parameters:
        o - The other value node whose kind we want to compare with.
        Returns:
        true if this and o represent the same logical node type, i.e. kind.