Class Operation2

    • Field Detail

      • left

        protected Expression left
        The left part of the operation (the first argument).
      • right

        protected Expression right
        The right part of the operation (the second argument).
      • type

        protected TypeInfo type
        The type of the result.
    • Method Detail

      • getType

        public TypeInfo getType()
        Description copied from class: Expression
        Returns the data type. The data type may be unknown before the optimization phase.
        Specified by:
        getType in interface Typed
        Specified by:
        getType in class Expression
        Returns:
        the data type
      • mapColumns

        public void mapColumns​(ColumnResolver resolver,
                               int level,
                               int state)
        Description copied from class: Expression
        Map the columns of the resolver to expression columns.
        Specified by:
        mapColumns in class Expression
        Parameters:
        resolver - the column resolver
        level - the subquery nesting level
        state - current state for nesting checks, initial value is Expression.MAP_INITIAL
      • setEvaluatable

        public void setEvaluatable​(TableFilter tableFilter,
                                   boolean value)
        Description copied from class: Expression
        Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.
        Specified by:
        setEvaluatable in class Expression
        Parameters:
        tableFilter - the table filter
        value - true if the table filter can return value
      • updateAggregate

        public void updateAggregate​(SessionLocal session,
                                    int stage)
        Description copied from class: Expression
        Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.
        Specified by:
        updateAggregate in class Expression
        Parameters:
        session - the session
        stage - select stage
      • isEverything

        public boolean isEverything​(ExpressionVisitor visitor)
        Description copied from class: Expression
        Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.
        Specified by:
        isEverything in class Expression
        Parameters:
        visitor - the visitor
        Returns:
        if the criteria can be fulfilled
      • getCost

        public int getCost()
        Description copied from class: Expression
        Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.
        Specified by:
        getCost in class Expression
        Returns:
        the estimated cost
      • getSubexpressionCount

        public int getSubexpressionCount()
        Description copied from class: Expression
        Returns count of subexpressions.
        Overrides:
        getSubexpressionCount in class Expression
        Returns:
        count of subexpressions
      • getSubexpression

        public Expression getSubexpression​(int index)
        Description copied from class: Expression
        Returns subexpression with specified index.
        Overrides:
        getSubexpression in class Expression
        Parameters:
        index - 0-based index
        Returns:
        subexpression with specified index, may be null