Class OrderedColumn

java.lang.Object
org.apache.derby.impl.sql.compile.QueryTreeNode
org.apache.derby.impl.sql.compile.OrderedColumn
All Implemented Interfaces:
Visitable
Direct Known Subclasses:
GroupByColumn, OrderByColumn

public abstract class OrderedColumn extends QueryTreeNode
An ordered column has position. It is an abstract class for group by and order by columns.
  • Field Details

    • UNMATCHEDPOSITION

      protected static final int UNMATCHEDPOSITION
      See Also:
    • columnPosition

      protected int columnPosition
  • Constructor Details

  • Method Details

    • isAscending

      boolean isAscending()
      Indicate whether this column is ascending or not. By default assume that all ordered columns are necessarily ascending. If this class is inherited by someone that can be desceneded, they are expected to override this method.
      Returns:
      true
    • isNullsOrderedLow

      boolean isNullsOrderedLow()
      Indicate whether this column should be ordered NULLS low. By default we assume that all ordered columns are ordered with NULLS higher than non-null values. If this class is inherited by someone that can be specified to have NULLs ordered lower than non-null values, they are expected to override this method.
      Returns:
      false
    • toString

      public 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 QueryTreeNode
      Returns:
      This object as a String
    • getColumnPosition

      int getColumnPosition()
      Get the position of this column
      Returns:
      The position of this column
    • setColumnPosition

      void setColumnPosition(int columnPosition)
      Set the position of this column