ABAP Bom按层展开的几种实现方法

*递归的方式实现FUNCTION zbomexplode.*"--------------------------------------------------------- *"*"Local Interface:*"IMPORTING*"REFERENCE(MATNR) TYPE  MATNR*"REFERENCE(WERKS) TYPE  WERKS_D*"TABLES*"PARENT STRUCTURE  SBOM*"CHILDREN STRUCTURE  SBOM*"EXCEPTIONS*"      NO_BOM_FOUND  *"----------------------------------------------------------  DATA: it_a TYPE TABLE OF sbom.  DATA: it_b TYPE TABLE OF sbom.  IF parent[] IS INITIAL.* first time that call to the FM    SELECT stpo~idnrk INTO TABLE it_a      FROM mast INNER JOIN stpo      ON mast~stlnr = stpo~stlnr      WHERE mast~matnr = matnr        AND mast~werks = werks.    IF it_a[] IS INITIAL.      RAISE no_bom_found.    ENDIF.  ELSE.    SELECT stpo~idnrk  INTO TABLE it_a      FROM mast      INNER JOIN stpo  ON mast~stlnr = stpo~stlnr      FOR ALL ENTRIES IN parent      WHERE mast~matnr = parent-matnr       AND mast~werks = werks.* if there is no any sub item, then stop the recursion     IF it_a[] IS INITIAL.    EXIT.  ENDIF.ENDIF.APPEND LINES OF it_a TO children.* get sub items recursivelyCALL FUNCTION 'Z_BOM_EXPLODE'  EXPORTING    matnr    = ''    werks    = werks  TABLES    parent   = it_a    children = it_b.APPEND LINES OF it_b TO children.* delete duplicate sub items at the endIF parent[] IS INITIAL.  SORT children BY matnr.  DELETE ADJACENT DUPLICATES FROM children.ENDIF.ENDFUNCTION.*使用循环代替递归的一种做法1，更便于做异常处理，程序运行时系统也不要维护递归堆栈。这个程序不好的地方在于要用两个itab频繁copy数据。FUNCTION zbomexplode1.*"--------------------------------------------------------- *"*"Local Interface:*"  IMPORTING*"     VALUE(MATNR) TYPE  MATNR*"     VALUE(WERKS) TYPE  WERKS_D *"  TABLES*"      CHILDREN STRUCTURE  SBOM *"  EXCEPTIONS*"      NO_BOM_FOUND  *"---------------------------------------------------------DATA: it_a      TYPE TABLE OF sbom,      it_b      TYPE TABLE OF sbom,      it_result TYPE TABLE OF sbom.SELECT stpo~idnrkINTO TABLE it_aFROM mast  INNER JOIN stpo ON mast~stlnr = stpo~stlnr       WHERE mast~matnr = matnr        AND mast~werks = werks.  APPEND LINES OF it_a TO it_result.  WHILE NOT it_a[] IS INITIAL.    SELECT stpo~idnrk             INTO TABLE it_b              FROM mast INNER JOIN stpo               ON mast~stlnr = stpo~stlnr             FOR ALL ENTRIES IN it_a              WHERE mast~matnr = it_a-matnr               AND mast~werks = werks.      APPEND LINES OF it_b TO it_result.      it_a[] = it_b[].    ENDWHILE.* delete duplicate sub items    SORT it_result BY matnr.    DELETE ADJACENT DUPLICATES FROM it_result.    children[] = it_result[].  ENDFUNCTION.  FUNCTION zbomexplode2.*"---------------------------------------------------------- *"*"Local Interface: *"  IMPORTING*"     VALUE(MATNR) TYPE  MATNR*"     VALUE(WERKS) TYPE  WERKS_D*"  TABLES*"      CHILDREN STRUCTURE  SBOM*"  EXCEPTIONS  *"      NO_BOM_FOUND*"----------------------------------------------------------    DATA: it_result TYPE TABLE OF sbom,          wa_bom    TYPE sbom.    SELECT stpo~idnrk       INTO TABLE it_result       FROM mast INNER JOIN stpo        ON mast~stlnr = stpo~stlnr      WHERE mast~matnr = matnr        AND mast~werks = werks.      LOOP AT it_result INTO wa_bom.        SELECT stpo~idnrk           APPENDING TABLE it_result          FROM mast INNER JOIN stpo            ON mast~stlnr = stpo~stlnr          WHERE mast~matnr = wa_bom-matnr            AND mast~werks = werks.        ENDLOOP.* delete duplicate sub items        sort it_result by matnr.        delete adjacent duplicates from it_result.        children[] = it_result[].      ENDFUNCTION.*调用BAPI实现 FUNCTION zbomexplode.*"--------------------------------------------------------- *"*"Local Interface: *"  IMPORTING*"     VALUE(MATNR) LIKE  MARA-MATNR*"     VALUE(WERKS) LIKE  MARC-WERKS OPTIONAL*"     VALUE(CAPID) LIKE  TC04-CAPID DEFAULT 'PP01'*"  TABLES*"      STB STRUCTURE  STPOX*"      RETURN STRUCTURE  BAPIRET2*"---------------------------------------------------------        IF werks IS INITIAL."Added in case external call does not know          werks = '1000'.        ENDIF.        IF capid IS INITIAL.          capid = 'PP01'.        ENDIF.        CALL FUNCTION 'CS_BOM_EXPL_MAT_V2'          EXPORTING            capid        = capid            datuv        = sy-datum            mehrs        = 'X'            mtnrv        = matnr            werks        = werks          TABLES            stb          = stb          EXCEPTIONS            no_bom_found = 1.        IF sy-subrc <> 0.          msg_typ = 'E'.          msg_id  = 'Z_EF'.          msg_no  = '002'.          msg_v1  = matnr.          IF NOT msg_typ IS INITIAL.* append error to table  RETURN            CALL FUNCTION 'BALW_BAPIRETURN_GET2'              EXPORTING                type      = msg_typ                cl        = msg_id                number    = msg_no                par1      = msg_v1                par2      = msg_v2                par3      = msg_v3                par4      = msg_v4                parameter = space                row       = space                field     = space              IMPORTING                return    = wa_return_tmp.            APPEND wa_return_tmp TO return.          ENDIF.        ENDIF.      ENDFUNCTION