Use GROUPING(x) function in a DECODE or CASE to enhance the result : GROUPING « Analytical Functions « Oracle PL/SQL Tutorial






SQL>
SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /

Table created.

SQL>
SQL> -- prepare data
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary,  City,       Description)
  2               values ('01','Jason',    'Martin',  to_date('19960725','YYYYMMDD'), to_date('20060
725','YYYYMMDD'), 1234.56, 'Toronto',  'Programmer')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary,  City,       Description)
  2                values('02','Alison',   'Mathews', to_date('19760321','YYYYMMDD'), to_date('19860
221','YYYYMMDD'), 6661.78, 'Vancouver','Tester')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary,  City,       Description)
  2                values('03','James',    'Smith',   to_date('19781212','YYYYMMDD'), to_date('19900
315','YYYYMMDD'), 6544.78, 'Vancouver','Tester')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary,  City,       Description)
  2                values('04','Celia',    'Rice',    to_date('19821024','YYYYMMDD'), to_date('19990
421','YYYYMMDD'), 2344.78, NULL,'Manager')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary,  City,       Description)
  2                values('05','Robert',   'Black',   to_date('19840115','YYYYMMDD'), to_date('19980
808','YYYYMMDD'), 2334.78, 'Vancouver','Tester')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary, City,        Description)
  2                values('06','Linda',    'Green',   to_date('19870730','YYYYMMDD'), to_date('19960
104','YYYYMMDD'), 4322.78,NULL,  'Tester')
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary, City,        Description)
  2                values('07','David',    'Larry',   to_date('19901231','YYYYMMDD'), to_date('19980
212','YYYYMMDD'), 7897.78,'New York',  NULL)
  3  /

1 row created.

SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,
                  Salary, City,        Description)
  2                values('08','James',    'Cat',     to_date('19960917','YYYYMMDD'), to_date('20020
415','YYYYMMDD'), 1232.78,'Vancouver', NULL)
  3  /

1 row created.

SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
  2  /

ID   FIRST_NAME LAST_NAME  START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- ---------- ---------- --------- --------- ---------- ---------- ---------------
01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia      Rice       24-OCT-82 21-APR-99    2344.78            Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4322.78            Tester
07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York
08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver

8 rows selected.

SQL>
SQL>
SQL> SELECT ROW_NUMBER() OVER(ORDER BY city, description) rn,
  2    count(*), city, description,
  3    DECODE(GROUPING(city),0,null,'Count by "CITY"')
  4        "Count CITY",
  5    DECODE(GROUPING (description), 0, null,'Count by "Description"')
  6        "Count Description"
  7  FROM employee
  8  GROUP BY CUBE(city, description);

        RN   COUNT(*) CITY       DESCRIPTION     Count CITY      Count Description
---------- ---------- ---------- --------------- --------------- ----------------------
         1          1 New York
         2          1 New York                                   Count by "Description"
         3          1 Toronto    Programmer
         4          1 Toronto                                    Count by "Description"
         5          3 Vancouver  Tester
         6          1 Vancouver
         7          4 Vancouver                                  Count by "Description"
         8          1            Manager
         9          1            Manager         Count by "CITY"
        10          1            Programmer      Count by "CITY"
        11          1            Tester

        RN   COUNT(*) CITY       DESCRIPTION     Count CITY      Count Description
---------- ---------- ---------- --------------- --------------- ----------------------
        12          4            Tester          Count by "CITY"
        13          2                                            Count by "Description"
        14          2                            Count by "CITY"
        15          8                            Count by "CITY" Count by "Description"

15 rows selected.

SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /

Table dropped.

SQL>








16.13.GROUPING
16.13.1.GROUPING() with a Single Column in a ROLLUP
16.13.2.Using DECODE() to Convert the Returned Value from GROUPING()
16.13.3.Using DECODE() and GROUPING() to Convert Multiple Column Values
16.13.4.Using GROUPING() with CUBE
16.13.5.Using the GROUPING SETS Clause
16.13.6.Computing the GROUPING Bit Vector
16.13.7.Using the GROUP_ID() Function
16.13.8.Eliminate duplicate rows using a HAVING clause that only allows rows whose GROUP_ID() is 0
16.13.9.Grouping with Rollup and Cube
16.13.10.Use GROUPING(x) function in a DECODE or CASE to enhance the result
16.13.11.Use the BREAK reporting tool to space the display conveniently
16.13.12.Getting Values and Subtotals in One Go with GROUPING SETS