SAP ABAP - 如何从一个输出中获得结果？ （循环内循环）

Question

我试图找出答案。来自City = Liverpool的客户表中的预订;但它似乎给了我错误的结果。什么可能出错？

Tables : scustom, 
         sbook.
Data : ABCtable type scustom,
       BKcnt(4) type N.

Clear BKcnt.

Select * from scustom into ABCtable where city = 'Liverpool'.

  Select * from sbook.
    BKcnt = BKcnt + 1.
  Endselect.

  Write: / ABCtable-id,
             15 ABCtable-name,
             50 BKcnt.
ENDSELECT.

Answer 1

对于＆＃34;可能出现什么问题＆＃34;，请参阅@knut的诊断：每个客户都得到相同的编号，因为您总是选择完整的sbook表。

对于这样的问题，最好将聚合，分组等留给数据库。试试这个版本：

report zz_count_sbook.

parameters: p_city type scustom-city lower case default 'Liverpool'.

data: id type scustom-id,
      name type scustom-name,
      count type i.

select customid name count(*) into (id,name,count)
       from scustom as c
       join sbook as b
       on b~customid = c~id
       where city eq p_city
       group by customid name.

  write: /    id,
           15 name,
           50 count.
endselect.

Answer 2

您的Select * from sbook.不包含任何其他条件。因此，您可以在每个循环中计算sbook中的所有条目，而不仅仅是与scustom中的条目相关联的条目。

我不知道表格，所以我无法给你正确的选择。

你数不高，你不需要自己计算：

Tables : scustom, 
         sbook.
Data : ABCtable type scustom,
       BKcnt(4) type N.

Clear BKcnt.

Select * from scustom into ABCtable where city = 'Liverpool'.

  Select count(*) into  BKcnt from sbook
    where <???> = ABCtable-<???>.   "I don't know your keys, replace <???> with the correct fields.

  Write: / ABCtable-id,
             15 ABCtable-name,
             50 BKcnt.
ENDSELECT.

（我希望我的select count是正确的。请使用语法检查器进行检查。至少在ABAP中有聚合函数！）

Answer 3

始终使用FOR ALL ENTRIES加入两个表以获得更好的效果。

SELECT * FROM scustom INTO TABLE ABCtable WHERE city = 'Liverpool'

SELECT count(*) INTO  BKcnt FROM sbook FOR ALL ENTRIES IN ABCtable
WHERE <???> = ABCtable-<???>