Analytic Example

The following example calculates, for each employee in the employees table, the average salary of the employees reporting to the same manager who were hired in the range just before through just after the employee:

SELECT manager_id, last_name, hire_date, salary,
   AVG(salary) OVER (PARTITION BY manager_id ORDER BY hire_date 
   ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS c_mavg
   FROM employees;

MANAGER_ID LAST_NAME                 HIRE_DATE     SALARY     C_MAVG
---------- ------------------------- --------- ---------- ----------
       100 Kochhar                   21-SEP-89      17000      17000
       100 De Haan                   13-JAN-93      17000      15000
       100 Raphaely                  07-DEC-94      11000 11966.6667
       100 Kaufling                  01-MAY-95       7900 10633.3333
       100 Hartstein                 17-FEB-96      13000 9633.33333
       100 Weiss                     18-JUL-96       8000 11666.6667
       100 Russell                   01-OCT-96      14000 11833.3333

SQL> SELECT x, y,
  2    AVG(y) OVER(ORDER BY x
  3      ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) ma
  4  FROM TestTable
  5  ORDER BY x;

         X          Y         MA
---------- ---------- ----------
         1          7          4
         2          1 3.33333333
         3          2 2.66666667
         4          5 4.66666667
         5          7 15.3333333
         6         34 24.3333333
         7         32 36.3333333
         8         43         54
         9         87         54
        10         32 43.6666667
        11         12         20
        12         16 30.3333333
        13         63         51
        14         74 57.6666667
        15         36 55.3333333
        16         56 31.3333333
        17          2         29

17 rows selected.