Package org.h2.expression.analysis

Class Window

  • public final class Window
extends java.lang.Object
    Window clause.

    • Constructor Summary

      Constructors 
      Constructor Description
      Window​(java.lang.String parent, java.util.ArrayList<Expression> partitionBy, java.util.ArrayList<QueryOrderBy> orderBy, WindowFrame frame)
      Creates a new instance of window clause.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static void appendOrderBy​(java.lang.StringBuilder builder, java.util.ArrayList<QueryOrderBy> orderBy, int sqlFlags, boolean forceOrderBy)
      Appends ORDER BY clause to the specified builder.
      Value getCurrentKey​(SessionLocal session)
      Returns the key for the current group.
      java.util.ArrayList<QueryOrderBy> getOrderBy()
      Returns ORDER BY clause.
      java.lang.StringBuilder getSQL​(java.lang.StringBuilder builder, int sqlFlags, boolean forceOrderBy)
      Appends SQL representation to the specified builder.
      WindowFrame getWindowFrame()
      Returns window frame, or null.
      boolean isOrdered()
      Returns true if window ordering clause is specified or ROWS unit is used.
      void mapColumns​(ColumnResolver resolver, int level)
      Map the columns of the resolver to expression columns.
      void optimize​(SessionLocal session)
      Try to optimize the window conditions.
      void setEvaluatable​(TableFilter tableFilter, boolean value)
      Tell the expression columns whether the table filter can return values now.
      java.lang.String toString()  
      void updateAggregate​(SessionLocal session, int stage)
      Update an aggregate value.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • Window

        public Window​(java.lang.String parent,
              java.util.ArrayList<Expression> partitionBy,
              java.util.ArrayList<QueryOrderBy> orderBy,
              WindowFrame frame)
        Creates a new instance of window clause.
        Parameters:
        parent - name of the parent window
        partitionBy - PARTITION BY clause, or null
        orderBy - ORDER BY clause, or null
        frame - window frame clause, or null

    • Method Detail

      • appendOrderBy

        public static void appendOrderBy​(java.lang.StringBuilder builder,
                                 java.util.ArrayList<QueryOrderBy> orderBy,
                                 int sqlFlags,
                                 boolean forceOrderBy)
        Appends ORDER BY clause to the specified builder.
        Parameters:
        builder - string builder
        orderBy - ORDER BY clause, or null
        sqlFlags - formatting flags
        forceOrderBy - whether synthetic ORDER BY clause should be generated when it is missing

      • optimize

        public void optimize​(SessionLocal session)
        Try to optimize the window conditions.
        Parameters:
        session - the session

      • setEvaluatable

        public void setEvaluatable​(TableFilter tableFilter,
                           boolean value)
        Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.
        Parameters:
        tableFilter - the table filter
        value - true if the table filter can return value
        See Also:
        Expression.setEvaluatable(TableFilter, boolean)

      • getOrderBy

        public java.util.ArrayList<QueryOrderBy> getOrderBy()
        Returns ORDER BY clause.
        Returns:
        ORDER BY clause, or null

      • getWindowFrame

        public WindowFrame getWindowFrame()
        Returns window frame, or null.
        Returns:
        window frame, or null

      • isOrdered

        public boolean isOrdered()
        Returns true if window ordering clause is specified or ROWS unit is used.
        Returns:
        true if window ordering clause is specified or ROWS unit is used

      • getCurrentKey

        public Value getCurrentKey​(SessionLocal session)
        Returns the key for the current group.
        Parameters:
        session - session
        Returns:
        key for the current group, or null

      • getSQL

        public java.lang.StringBuilder getSQL​(java.lang.StringBuilder builder,
                                      int sqlFlags,
                                      boolean forceOrderBy)
        Appends SQL representation to the specified builder.
        Parameters:
        builder - string builder
        sqlFlags - formatting flags
        forceOrderBy - whether synthetic ORDER BY clause should be generated when it is missing
        Returns:
        the specified string builder
        See Also:
        Expression.getSQL(StringBuilder, int, int)

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object