Skip Headers

Oracle® Database SQL Reference
10g Release 1 (10.1)

Part Number B10759-01
Go to Documentation Home
Home
Go to Book List
Book List
Go to Table of Contents
Contents
Go to Index
Index
Go to Master Index
Master Index
Go to Feedback page
Feedback

Go to previous page
Previous
Go to next page
Next
View PDF

GROUP_ID


Syntax

group_id::=
Description of group_id.gif follows
Description of the illustration group_id.gif


Purpose

GROUP_ID distinguishes duplicate groups resulting from a GROUP BY specification. It is useful in filtering out duplicate groupings from the query result. It returns an Oracle NUMBER to uniquely identify duplicate groups. This function is applicable only in a SELECT statement that contains a GROUP BY clause.

If n duplicates exist for a particular grouping, then GROUP_ID returns numbers in the range 0 to n-1.


Examples

The following example assigns the value 1 to the duplicate co.country_region grouping from a query on the sample tables sh.countries and sh.sales:

SELECT co.country_region, co.country_subregion,
   SUM(s.amount_sold) "Revenue",
   GROUP_ID() g
FROM sales s, customers c, countries co
WHERE s.cust_id = c.cust_id AND
   c.country_id = co.country_id AND
   s.time_id = '1-JAN-00' AND
   co.country_region IN ('Americas', 'Europe')
GROUP BY co.country_region,
   ROLLUP (co.country_region, co.country_subregion);

COUNTRY_REGION       COUNTRY_SUBREGION       Revenue          G
-------------------- -------------------- ---------- ----------
Americas             Northern America         220844          0
Americas             Southern America          10872          0
Europe               Eastern Europe            12751          0
Europe               Western Europe           558686          0
Americas                                      231716          0
Europe                                        571437          0
Americas                                      231716          1
Europe                                        571437          1

To ensure that only rows with GROUP_ID < 1 are returned, add the following HAVING clause to the end of the statement :

HAVING GROUP_ID() < 1