Syntax options:

       ORDER BY integer
       ORDER BY value-expr

    Specifies the order of rows for the result table. SQL sorts
    the rows from the intermediate result table by the values of
    expressions specified in the ORDER BY clause. The intermediate
    result table is the result table SQL produces when it evaluates
    the preceding clause in the select expression (HAVING, GROUP BY,
    WHERE, or FROM).

    You can refer to columns in the ORDER BY clause in two ways:

    o  By a value expression

    o  By column number, where the integer you specify indicates the
       left-to-right position of the column in the result table

    You must use an integer to identify a column in the ORDER BY
    clause if that column in the select list is derived from a
    function, an arithmetic expression, or the result of a UNION,
    MINUS, EXCEPT, or INTERSECT operator.

    Whether you identify expressions in an ORDER BY clause using a
    name or using a number, the expressions are called sort keys.

    When you use multiple sort keys, SQL treats the first expression
    as the major sort key and successive keys as minor sort keys.
    That is, it first sorts the rows into groups based on the first
    value expression. Then, it uses the second value expression to
    sort the rows within each group, and so on. Unless you specify
    a sort key for every column in the result table, rows with
    identical values for the last sort key specified will be in
    arbitrary order.

    The following example illustrates using the ORDER BY clause with
    a value expression.

    SQL> SELECT * FROM EMPLOYEES
    cont> ORDER BY EXTRACT (YEAR FROM BIRTHDAY),
    cont>  TRIM(FIRST_NAME) || TRIM(LAST_NAME);
     00190         O'Sullivan       Rick         G.
       78 Mason Rd.                NULL                        Fremont
          NH      03044         M      12-Jan-1923   1             None
     00231         Clairmont        Rick         NULL
       92 Madiso7 Drive            NULL                        Chocorua
          NH      03817         M      23-Dec-1924   2             None
     00183         Nash             Walter       V.
       197 Lantern Lane            NULL                        Fremont
          NH      03044         M      19-Jan-1925   1             None
     00177         Kinmonth         Louis        NULL
       76 Maple St.                NULL                        Etna
          NH      03750         M       7-Apr-1926   1             None
     00240         Johnson          Bill         R.
       20 South St                 NULL                        Milford
          NH      03055         M      13-Apr-1927   2             None
       .
       .
       .