您知道从没有父节点ID的表生成父子层次结构的有效方法吗。父子关系应该是可切换的。所有这些都应该在ABAP中完成。
示例数据：
Color producer weight Airplane(key)
green CompanyA 330 A350
green CompanyA 222 A320
green CompanyB 222 B450
yellow CompanyA 330 H450
我想基于以下行生成一个父子关系：生产者权重飞机和忽略颜色。然后我会改变它并使用：色重飞机和忽略生产者
最后，我需要一个看起来像"；生产商重量的飞机；
CompanyA CompanyB
330 222 222
A350 A320 B450
H450
在内部表格中，末尾应该是这样的
ID attribute value H_level parentID
1 producer CompanyA 1
2 weight 330 2 1
3 airplane A350 3 2
.....
有人有一个有效的好主意吗？非常感谢。
这里有一个简单的树构建算法，可以满足您的需要。
请注意，该算法在性能方面没有进行优化。如果您管理大量数据，您可能需要修改某些方面，例如使用SORTED或HASHED而不是STANDARD表来改进查找READ tables。
该算法也没有进行重构以获得最佳的代码样式。例如，干净的代码表明我们可能想要提取几个方法来提高可读性。
CLASS hierarchy_builder DEFINITION
PUBLIC FINAL CREATE PUBLIC.
PUBLIC SECTION.
TYPES:
BEGIN OF ts_input,
color TYPE string,
producer TYPE string,
weight TYPE string,
airplane TYPE string,
END OF ts_input.
TYPES tt_input TYPE
STANDARD TABLE OF ts_input
WITH EMPTY KEY.
TYPES tt_attributes TYPE string_table.
TYPES:
BEGIN OF ts_output,
id TYPE string,
attribute TYPE string,
value TYPE string,
level TYPE i,
parent_id TYPE string,
END OF ts_output.
TYPES tt_output
TYPE STANDARD TABLE OF ts_output
WITH EMPTY KEY.
CLASS-METHODS build_hierarchy
IMPORTING
it_data TYPE tt_input
it_hierarchy TYPE tt_attributes
RETURNING
VALUE(rt_result) TYPE tt_output.
ENDCLASS.
CLASS hierarchy_builder IMPLEMENTATION.
METHOD build_hierarchy.
DATA(lv_parent_attribute) = ``.
DATA(lv_next_id) = 1.
LOOP AT it_hierarchy INTO DATA(lv_child_attribute).
DATA(lv_level) = sy-tabix.
LOOP AT it_data INTO DATA(ls_data).
DATA(lv_parent_id) = ``.
ASSIGN COMPONENT lv_child_attribute
OF STRUCTURE ls_data
TO FIELD-SYMBOL(<lv_child_value>).
IF lv_parent_attribute IS NOT INITIAL.
ASSIGN COMPONENT lv_parent_attribute
OF STRUCTURE ls_data
TO FIELD-SYMBOL(<lv_parent_value>).
READ TABLE rt_result
INTO DATA(ls_parent)
WITH KEY
attribute = lv_parent_attribute
value = <lv_parent_value>.
lv_parent_id = ls_parent-id.
ENDIF.
READ TABLE rt_result
TRANSPORTING NO FIELDS
WITH KEY
attribute = lv_child_attribute
value = <lv_child_value>
parent_id = lv_parent_id.
IF sy-subrc <> 0.
INSERT VALUE #(
id = |{ lv_next_id }|
attribute = lv_child_attribute
value = <lv_child_value>
level = lv_level
parent_id = lv_parent_id )
INTO TABLE rt_result.
lv_next_id += 1.
ENDIF.
ENDLOOP.
lv_parent_attribute = lv_child_attribute.
ENDLOOP.
ENDMETHOD.
ENDCLASS.
通过以下单元测试进行验证。它代表了你举的例子：
CLASS ltc_unit_tests DEFINITION
FOR TESTING RISK LEVEL HARMLESS DURATION SHORT.
PRIVATE SECTION.
METHODS builds_example FOR TESTING.
ENDCLASS.
CLASS ltc_unit_tests IMPLEMENTATION.
METHOD builds_example.
DATA(lt_data) =
VALUE hierarchy_builder=>tt_input(
( color = 'green' producer = 'CompanyA' weight = '330' airplane = 'A350' )
( color = 'green' producer = 'CompanyA' weight = '222' airplane = 'A320' )
( color = 'green' producer = 'CompanyB' weight = '222' airplane = 'B450' )
( color = 'yellow' producer = 'CompanyA' weight = '330' airplane = 'H450' ) ).
DATA(lt_hierarchy) =
VALUE hierarchy_builder=>tt_attributes(
( `PRODUCER` )
( `WEIGHT` )
( `AIRPLANE` ) ).
DATA(lt_result) =
hierarchy_builder=>build_hierarchy(
it_data = lt_data
it_hierarchy = lt_hierarchy ).
DATA(lt_expected) =
VALUE hierarchy_builder=>tt_output(
( id = '1' attribute = 'PRODUCER' value = 'CompanyA' level = 1 parent_id = '' )
( id = '2' attribute = 'PRODUCER' value = 'CompanyB' level = 1 parent_id = '' )
( id = '3' attribute = 'WEIGHT' value = '330' level = 2 parent_id = '1' )
( id = '4' attribute = 'WEIGHT' value = '222' level = 2 parent_id = '1' )
( id = '5' attribute = 'WEIGHT' value = '222' level = 2 parent_id = '2' )
( id = '6' attribute = 'AIRPLANE' value = 'A350' level = 3 parent_id = '3' )
( id = '7' attribute = 'AIRPLANE' value = 'A320' level = 3 parent_id = '4' )
( id = '8' attribute = 'AIRPLANE' value = 'B450' level = 3 parent_id = '4' )
( id = '9' attribute = 'AIRPLANE' value = 'H450' level = 3 parent_id = '3' ) ).
cl_abap_unit_assert=>assert_equals(
act = lt_result
exp = lt_expected ).
ENDMETHOD.
ENDCLASS.