Mega Code Archive
Using DECODE() and GROUPING() to Convert Multiple Column Values
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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('20060725','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('19860221','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('19900315','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('19990421','YYYYMMDD'), 2344.78, 'Vancouver','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('19980808','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('19960104','YYYYMMDD'), 4322.78,'New York', '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('19980212','YYYYMMDD'), 7897.78,'New York', 'Manager')
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('20020415','YYYYMMDD'), 1232.78,'Vancouver', 'Tester')
3 /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DATE END_DATE SALARY CITY DESCRIPTION
---- ---------- ---------- ----------- ----------- ---------- ---------- ---------------
01 Jason Martin 1996-JUL-25 2006-JUL-25 1234.56 Toronto Programmer
02 Alison Mathews 1976-MAR-21 1986-FEB-21 6661.78 Vancouver Tester
03 James Smith 1978-DEC-12 1990-MAR-15 6544.78 Vancouver Tester
04 Celia Rice 1982-OCT-24 1999-APR-21 2344.78 Vancouver Manager
05 Robert Black 1984-JAN-15 1998-AUG-08 2334.78 Vancouver Tester
06 Linda Green 1987-JUL-30 1996-JAN-04 4322.78 New York Tester
07 David Larry 1990-DEC-31 1998-FEB-12 7897.78 New York Manager
08 James Cat 1996-SEP-17 2002-APR-15 1232.78 Vancouver Tester
8 rows selected.
SQL>
SQL> --Using DECODE() and GROUPING() to Convert Multiple Column Values
SQL>
SQL>
SQL> SELECT DECODE(GROUPING(city), 1, 'All cities', city) AS City,
2 DECODE(GROUPING(description), 1, 'All Descriptions', description) AS Description,
3 SUM(salary)
4 FROM employee
5 GROUP BY ROLLUP(city, description);
CITY DESCRIPTION SUM(SALARY)
---------- ---------------- -----------
Toronto Programmer 1234.56
Toronto All Descriptions 1234.56
New York Tester 4322.78
New York Manager 7897.78
New York All Descriptions 12220.56
Vancouver Tester 16774.12
Vancouver Manager 2344.78
Vancouver All Descriptions 19118.9
All cities All Descriptions 32574.02
9 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL>
SQL>
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