ABAP/4 ОКМ ДМ экономическая информатика 4GL Теория и практика обработки информации

Компьютерный язык ABAP/4 - ключевые слова

GROUP-BY clause

Variants

1. ... GROUP BY f1 ... fn
2. ... GROUP BY (itab)

Variant 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 database fields f1 ... fn .

... GROUP BY f1 ... fn always requires a list in the SELECT clause . Each field f1 ... fn must be specified in this list If you use aggregate functions together with one or more database fields in the SELECT clause , you must also all the database fields not specified by one of the aggregate functions under GROUP BY f1 ... fn .

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.

Variant 2

... GROUP BY (itab)

Effect

Works like GROUP BY f1 ... fn if the internal table itab contains the list f1 ... fn as ABAP/4 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:   GTAB(72) OCCURS 5 WITH HEADER LINE,
        FTAB(72) OCCURS 5 WITH HEADER LINE,
        COUNT TYPE I.

REFRESH: GTAB, FTAB.
FTAB = 'CITYFROM COUNT( * ) AS COUNT'. APPEND FTAB.
GTAB = 'CITYFROM'.                     APPEND GTAB.

SELECT DISTINCT (FTAB)
       INTO CORRESPONDING FIELDS OF WA
       FROM SPFLI
       WHERE
         CARRID   = 'LH'
       GROUP BY (GTAB).
  WRITE: / WA-CITYFROM, WA-COUNT.
ENDSELECT.

Note

Performance
If possible, you should use the aggregate functions (for example, to determine the minimum value of a database field).

Index
© SAP AG 1996

ABAP/4 ОКМ ДМ экономическая информатика 4GL Теория и практика обработки информации

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