Use of group by and having clause

Question

hi frnds
can anybody explain me the use of group by an having clause in select state ment

Answer 1

Hi Rohit,
1. GROUP BY f1 ... fn
2. GROUP BY (itab)
1. GROUP BY f1 ... fn
Effect
Groups database table data in a SELECT command on one line in the result set. A group is a set of lines which all have the same values in each column determined by the field descriptors f1 ... fn.
... GROUP BY f1 ... fn always requires a list in the SELECT clause. If you use field descriptors without an aggregate funciton in the SELECT clause, you must list them in the GROUP BY f1 ... fn clause.
Example
Output the number of passengers, the total weight and the average weight of luggage for all Lufthansa flights on 28.02.1995:
TABLES SBOOK.
DATA:  COUNT TYPE I, SUM TYPE P DECIMALS 2, AVG TYPE F.
DATA:  CONNID LIKE SBOOK-CONNID.
SELECT CONNID COUNT( * ) SUM( LUGGWEIGHT ) AVG( LUGGWEIGHT )
       INTO (CONNID, COUNT, SUM, AVG)
       FROM SBOOK
       WHERE
         CARRID   = 'LH'       AND
         FLDATE   = '19950228'
       GROUP BY CONNID.
  WRITE: / CONNID, COUNT, SUM, AVG.
ENDSELECT.
Note
... GROUP BY f1 ... fn is not supported for pooled and cluster tables.
2. GROUP BY (itab)
Effect
Works like GROUP BY f1 ... fn if the internal table itab contains the list f1 ... fn as ABAP source code. The internal table itab can only have one field. This field must be of the type C and should not be more than 72 characters long. itab must be enclosed in parentheses and there should be no blanks between the parentheses and the table name.
Note
The same restrictions apply to this variant as to GROUP BY f1 ... fn.
Example
Output all Lufthansa departure points with the number of destinations:
TABLES: SPFLI.
DATA:   BEGIN OF WA.
          INCLUDE STRUCTURE SPFLI.
DATA:     COUNT TYPE I.
DATA:   END OF WA.
DATA:   WA_TAB(72) TYPE C,
        GTAB LIKE TABLE OF WA_TAB,
        FTAB LIKE TABLE OF WA_TAB,
        COUNT TYPE I.
CLEAR: GTAB, FTAB.
WA_TAB = 'COTYFROM COUNT( * ) AS COUNT'. APPEND FTAB.
APPEND WA_TAB TO FTAB.
WA_TAB = 'CITYFROM'.
APPEND WA_TAB TO GTAB.
SELECT DISTINCT (FTAB)
       INTO CORRESPONDING FIELDS OF WA
       FROM SPFLI
       WHERE
         CARRID   = 'LH'
       GROUP BY (GTAB).
  WRITE: / WA-CITYFROM, WA-COUNT.
ENDSELECT.
Regards,
Susmitha