首先, 解释BDC这三个英文的意思, 普遍都认同是(Batch Data Communication). 然后下面是一些相关的术语解释:

Batch Input: 批输入, 用于大批量, 非实时性( 对速度要求比较低) 的数据传输 使用BDC_OPEN_GROUP, BDC_INSERT_GROUP, BDC_CLOSE_GROUP这几个function实现批输入会话的操作. 然后通过批输入会话将数据传输到SAP.

Call Transaction:　调用事务, 与批输入的差异主要是在于数据传输过程不生成批输入会话, 数据在程序运行过程中直接通过调用CALL TRANSACTION USING BDC表传输至SAP.

Direct Input:　直接输入, 其主要优点是速度最快, 不生成会话, 数据被直接输入至SAP. 不存在事务屏幕处理过程(批输入和调用事务中均包含该过程), 直接输入的效率较高, 系统负载较小. 使用TCODE BMV0.

但是我们不该把BDC技术只局限于录屏幕, 批输入和调用事务上, 其实以下技术都可以实现BDC, 比如BAPI, IDOC.

BAPI:　业务应用程序接口, SAP作为一个完善的系统, 每个应用中都有包含标准的数据传输接口.

IDOC: 中间文档, ALE和EDI属于系统间数据传输的接口, IDOC中包含数据结构的定义和数据的处理逻辑, 是传输的介质.

这个图参照了黄佳写的<<SAP业务数据传输指南>>.  下面我来详细举例一下其中几种技术.

一, 调用事务, 主要使用该语句

CALL TRANSACTION '事务代码' USING bdc表 MODE m UPDATE 'S' MESSAGES INTO mssg.

bdc表是参考bdcdata结构定义的内表, 主要存储屏幕处理所需要的关键数据, 其结构如下:

字段名	类型	长度	小数	描述
PROGRAM	CHAR	40	0	BDC module pool
DYNPRO	NUMC	4	0	BDC Screen number
DYNBEGIN	CHAR	1	0	BDC screen start
FNAM	CHAR	132	0	Field name
FVAL	CHAR	132	0	BDC field value

MODE m 是指Processing Mode, 共有4种处理模式:

模式	英文描述
A	Display all screens
E	Display errors
N	Background processing
P	Background processing; debugging possible

UPDATE 'S'  是指更新模式, 共有3种更新模式,一般使用'S'模式:

模式	描述
A	异步
S	同步
L	本地

MESSAGES INTO mssg 的意思是将处理信息导入到一个参考bdcmsgcoll结构的内表, 方便查错.

下面是一个上传物料中文描述的简单例子:

*&---------------------------------------------------------------------* *& Report  ZBDC_TEST1 *& 调用事务 *&---------------------------------------------------------------------* *&  Author: Jun *& *&---------------------------------------------------------------------*  REPORT  zbdc_test1.  ************************************************************************ * D A T A ************************************************************************  CONSTANTS: c_def_path LIKE rlgrap-filename VALUE 'c:\file.txt'. DATA: BEGIN OF mssg OCCURS 0.         INCLUDE STRUCTURE bdcmsgcoll. DATA: END OF mssg.   DATA: BEGIN OF zitab_bdc OCCURS 0.         INCLUDE STRUCTURE bdcdata. DATA: END OF zitab_bdc.  DATA: BEGIN OF t_main OCCURS 0,       matnr(18),       maktx(40),       END OF t_main.  DEFINE dynpro.    CLEAR zitab_bdc.   IF &1 = 'X'.      MOVE: 'X' TO zitab_bdc-dynbegin,                 &2  TO zitab_bdc-program,                 &3 TO zitab_bdc-dynpro.    ELSE.      MOVE: &2 TO zitab_bdc-fnam,                 &3 TO zitab_bdc-fval.    ENDIF.    APPEND zitab_bdc.  END-OF-DEFINITION.  SELECTION-SCREEN BEGIN OF BLOCK sc1 WITH FRAME TITLE text-s01. PARAMETER: f_cap TYPE rlgrap-filename OBLIGATORY DEFAULT c_def_path. PARAMETER: m TYPE ctu_mode DEFAULT 'N'. SELECTION-SCREEN END OF BLOCK sc1.   ************************************************************************ * S T A R T O F S E L E C T I O N ************************************************************************ START-OF-SELECTION.   WRITE : / 'Start creation of BDC session',sy-mandt,sy-uname,sy-uzeit.   PERFORM get_codepage.   PERFORM call_upload TABLES t_main USING f_cap.   PERFORM update_data.    WRITE: / 'Finished!'.   ************************************************************************ * F O R M S ************************************************************************ *&---------------------------------------------------------------------* *& *&      Form  GET_CODEPAGE *&---------------------------------------------------------------------* FORM get_codepage.    DATA: cncoden TYPE abap_encod,         cncode type  CPCODEPAGE.    CALL FUNCTION 'NLS_GET_FRONTEND_CP'     EXPORTING       langu                 = '1'     IMPORTING       frontend_codepage     = cncode     EXCEPTIONS       illegal_syst_codepage = 21       no_frontend_cp_found  = 23       internal_or_db_error  = 25.   MOVE: cncode TO cncoden. ENDFORM.  *&---------------------------------------------------------------------* *& *&      Form  CALL_UPLOAD *&---------------------------------------------------------------------*  FORM call_upload TABLES p_tab USING p_fname.    DATA: tmp_filename TYPE string.    tmp_filename = p_fname.       CALL METHOD cl_gui_frontend_services=>gui_download       EXPORTING         filename                = tmp_filename         write_field_separator     = 'X'         codepage                = cncoden       CHANGING         data_tab                = p_tab       EXCEPTIONS         file_write_error        = 1         no_batch                = 2         gui_refuse_filetransfer = 3         invalid_type            = 4         no_authority            = 5         unknown_error           = 6         header_not_allowed      = 7         separator_not_allowed   = 8         filesize_not_allowed    = 9         header_too_long         = 10         dp_error_create         = 11         dp_error_send           = 12         dp_error_write          = 13         unknown_dp_error        = 14         access_denied           = 15         dp_out_of_memory        = 16         disk_full               = 17         dp_timeout              = 18         file_not_found          = 19         dataprovider_exception  = 20         control_flush_error     = 21         not_supported_by_gui    = 22         error_no_gui            = 23         OTHERS                  = 24.  if sy-subrc <> 0. * MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO *            WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4. endif.  ENDFORM.                    "call_upload *&---------------------------------------------------------------------* *&      Form  update_data *&---------------------------------------------------------------------* *       text *----------------------------------------------------------------------* FORM update_data.    REFRESH zitab_bdc.    LOOP AT t_main.     PERFORM call_transaction.   ENDLOOP. ENDFORM.                    "update_data  *&---------------------------------------------------------------------* *&      Form  call_transaction *&---------------------------------------------------------------------* *       text *----------------------------------------------------------------------* FORM call_transaction.  dynpro: 'X'   'SAPLMGMM'  '0060',              ' '   'RMMG1-MATNR'   t_main-matnr,              ' '   'BDC_OKCODE'    '/00'.  dynpro: 'X'   'SAPLMGMM'   '0070',              ' '   'MSICHTAUSW-KZSEL(01)'  'X',              ' '   'BDC_OKCODE'  '=ENTR'.  dynpro: 'X'   'SAPLMGMM'    '4004',              ' '   'BDC_OKCODE'  '=ZU01'.  dynpro:  'X'   'SAPLMGMM'    '4300',               ' '   'SKTEXT-SPRAS(02)'  'ZH',               ' '   'SKTEXT-MAKTX(02)'  t_main-maktx,               ' '   'BDC_OKCODE'    '=BU'.     CALL TRANSACTION 'MM02' USING zitab_bdc MODE m UPDATE 'S' MESSAGES INTO mssg.    IF sy-subrc NE 0.     MESSAGE ID sy-msgid TYPE 'S' NUMBER sy-msgno             WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.   ENDIF.   REFRESH: zitab_bdc,mssg.  ENDFORM.                    " CALL_TRANSACTION  

二, 批输入, 主要使用BDC_OPEN_GROUP, BDC_INSERT_GROUP, BDC_CLOSE_GROUP这几个function实现批输入会话的操作. 然后通过批输入会话将数据传输到SAP.

以下是Batch Input的例子, 是把前面的程序改了一下完成的, 注意红色的地方就是不同处:

*&---------------------------------------------------------------------* *& Report  ZBDC_TEST2 *&  批输入 *&---------------------------------------------------------------------* *&  Author: Jun *& *&---------------------------------------------------------------------*  REPORT  zbdc_test2.  ************************************************************************ * D A T A ************************************************************************  CONSTANTS: c_def_path LIKE rlgrap-filename VALUE 'c:\file.txt'.  DATA: BEGIN OF zitab_bdc OCCURS 0.         INCLUDE STRUCTURE bdcdata. DATA: END OF zitab_bdc.  DATA: BEGIN OF t_main OCCURS 0,       matnr(18),       maktx(40),       END OF t_main.  DEFINE dynpro.    CLEAR zitab_bdc.   IF &1 = 'X'.      MOVE: 'X' TO zitab_bdc-dynbegin,         &2  TO zitab_bdc-program,         &3 TO zitab_bdc-dynpro.    ELSE.      MOVE: &2 TO zitab_bdc-fnam,  &3 TO zitab_bdc-fval.    ENDIF.    APPEND zitab_bdc.  END-OF-DEFINITION.  SELECTION-SCREEN BEGIN OF BLOCK sc1 WITH FRAME TITLE text-s01. PARAMETER: f_cap TYPE rlgrap-filename OBLIGATORY DEFAULT c_def_path. SELECTION-SCREEN END OF BLOCK sc1.   ************************************************************************ * S T A R T O F S E L E C T I O N ************************************************************************ START-OF-SELECTION.   WRITE : / 'Start creation of BDC session',sy-mandt,sy-uname,sy-uzeit.   PERFORM get_codepage.   PERFORM call_upload TABLES t_main USING f_cap.   PERFORM update_data.    WRITE: / 'Finished!'.   ************************************************************************ * F O R M S ************************************************************************ *&---------------------------------------------------------------------* *& *&      Form  GET_CODEPAGE *&---------------------------------------------------------------------* FORM get_codepage.    DATA: cncoden TYPE abap_encod,         cncode type  CPCODEPAGE.    CALL FUNCTION 'NLS_GET_FRONTEND_CP'     EXPORTING       langu                 = '1'     IMPORTING       frontend_codepage     = cncode     EXCEPTIONS       illegal_syst_codepage = 21       no_frontend_cp_found  = 23       internal_or_db_error  = 25.   MOVE: cncode TO cncoden. ENDFORM.  *&---------------------------------------------------------------------* *& *&      Form  CALL_UPLOAD *&---------------------------------------------------------------------*  FORM call_upload TABLES p_tab USING p_fname.    DATA: tmp_filename TYPE string.    tmp_filename = p_fname.       CALL METHOD cl_gui_frontend_services=>gui_download       EXPORTING         filename                = tmp_filename  write_field_separator     = 'X'         codepage                = cncoden       CHANGING         data_tab                = p_tab       EXCEPTIONS         file_write_error        = 1         no_batch                = 2         gui_refuse_filetransfer = 3         invalid_type            = 4         no_authority            = 5         unknown_error           = 6         header_not_allowed      = 7         separator_not_allowed   = 8         filesize_not_allowed    = 9         header_too_long         = 10         dp_error_create         = 11         dp_error_send           = 12         dp_error_write          = 13         unknown_dp_error        = 14         access_denied           = 15         dp_out_of_memory        = 16         disk_full               = 17         dp_timeout              = 18         file_not_found          = 19         dataprovider_exception  = 20         control_flush_error     = 21         not_supported_by_gui    = 22         error_no_gui            = 23         OTHERS                  = 24.  if sy-subrc <> 0. * MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO *            WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4. endif.  ENDFORM.                    "call_upload *&---------------------------------------------------------------------* *&      Form  update_data *&---------------------------------------------------------------------* *       text *----------------------------------------------------------------------* FORM update_data.  

    REFRESH zitab_bdc.    LOOP AT t_main.     PERFORM  batch_input.    ENDLOOP.   ENDFORM.                    "update_data  *&---------------------------------------------------------------------* *&      Form  batch_input  *&---------------------------------------------------------------------* *       text *----------------------------------------------------------------------* FORM batch_input.  dynpro:   'X'   'SAPLMGMM'  '0060',   ' '   'RMMG1-MATNR'   t_main-matnr,   ' '   'BDC_OKCODE'    '/00'.    dynpro:   'X'   'SAPLMGMM'   '0070',   ' '   'MSICHTAUSW-KZSEL(01)'  'X',   ' '   'BDC_OKCODE'  '=ENTR'.  dynpro:   'X'   'SAPLMGMM'    '4004',   ' '   'BDC_OKCODE'  '=ZU01'.  dynpro:   'X'   'SAPLMGMM'    '4300',   ' '   'SKTEXT-SPRAS(02)'  'ZH',   ' '   'SKTEXT-MAKTX(02)'  t_main-maktx,   ' '   'BDC_OKCODE'    '=BU'.      REFRESH: zitab_bdc.  ENDFORM.   

三, BAPI是SAP标准的API, 在多系统的环境下,我们可以通过ALE/EDI技术使用RFC和BAPI实现数据传输工作. 但是也可以自己编写程序实现本地执行传输工作. 下面是一个使用BAPI传输PO的例子:

*&---------------------------------------------------------------------* *& Report  ZCON0026 *& *&---------------------------------------------------------------------* *&  Author: Jun *& *&---------------------------------------------------------------------*  REPORT  ZCON0026.  FIELD-SYMBOLS : .  DATA:g_ebeln TYPE ekko-ebeln.   "Purchasing Document Header DATA:g_mtart TYPE mtart.   DATA:BEGIN OF it_msg1 OCCURS 0,           ebeln LIKE ekpo-ebeln,           type like bapiret2-type,           message LIKE bapiret2-message,           old_po like ekpo-ebeln,      END  OF it_msg1.   DATA:g_poitem TYPE ebelp.   "Item Number of Purchasing Document DATA:g_meng LIKE ekpo-menge.    "Purchase Order Quantity DATA:l_intern TYPE kcde_cells OCCURS 0 WITH HEADER LINE. DATA:len_str TYPE i,      l_index TYPE i.  DATA:BEGIN OF it_data OCCURS 0, *       doc_type(004),   

       po(010),  "PO NO        material(018),        vendor(010),        invoice_no(15),  "Invoice Number(Header text)        pmnttrms(004),   "Paymentterms        quantity(017),        doc_date(008),        gr_to_date(008), "Delivery date        shippingin(10),  "Ship Date(Header Text)        eta_hk(10),      "Date of ETA HK(Header Text)        trsp_metd(10),   "Transportion Method(Header Text)        container_no(20),  "COntainer Number(Header Text)        lc_number(20),   "LC Number(Header Text)        load_date(10),   "Load Date(Header Text)        arr_hk(10),      "Date of Arr. Date(Header Text)        remark(20),      "Header remark(Header Text)        currency(005),        cond_pb00(038),  "Net price        cond_p_unt(5),    "Price Unit  END OF it_data. DATA:BEGIN OF it_head OCCURS 0,        comp_code(4),    "Company Code        doc_type(004),   "######        po_number(010),        po(010),        vendor(010),     "######        doc_date(008),   "####        purch_org(004),  "####        pur_group(003),  "####        pmnttrms(004),   "####        incoterms1(003), "######        incoterms2(028), "######        currency(005),   "####        exch_rate(014),  "##        text_pohzs(132), "Header Remark        shippingin(132), "SHIPPING INSTRUCTION        prppayment(132), "PAYMENT TERM FOR PRP        delivery(132),   "DELIVERY        attention(132),  "ATTENTION        name_2(040),                                         "#####2        name_3(040),                                         "#####3        name_4(040),                                         "#####4        street(040),     "##        str_suppl2(040), "##4        location(040),   "##5        postl_cod1(010), "######        country(003),    "####        tel1_numbr(030), "##        fax_number(030), "##        billty(002),     "########        billpo(010),     "######        purcty(002),     "########        purcpo(010),     "#####        patety(002),     "########        patepo(010),     "######        shipty(002),     "########        shippo(010),     "######        COLLECT_NO(010),   "Collective Number      END   OF it_head. DATA:BEGIN OF it_item OCCURS 0,        po_number(010),  "        po(010),        acctasscat(001), "######        item_cat(001),   "####        material(018),   "######        short_text(040), "####        quantity(017),   "######        po_unit(003),    "####        gr_to_date(008), "####        cond_pb00(038),  "Net Price        cond_p_unt(005), "########        cond_za00(038),  "UNZ#UTE######        matl_group(009), "####        plant(004),      "##        over_dlv_tol(005),"########        tax_code(002),    "##/######        costcenter(010),  "####        poit_text(132),   "PO####        pobz_text(132),   "PO####        valuepart1(240),  "Exfact Date        valuepart2(240),  "Arr.HK Date      END OF it_item. DATA:g_menge LIKE ekpo-netpr. ****************************************************************** *   PARAMETERS & SELECTION-OPTIONS ****************************************************************** SELECTION-SCREEN BEGIN OF BLOCK sel  WITH FRAME TITLE text-001. PARAMETERS:p_upload RADIOBUTTON GROUP radi,            p_uptemp RADIOBUTTON GROUP radi. PARAMETERS:p_flag  AS CHECKBOX . SELECTION-SCREEN END OF BLOCK sel.  SELECTION-SCREEN BEGIN OF BLOCK mod  WITH FRAME TITLE text-002. PARAMETERS:p_file LIKE  rlgrap-filename DEFAULT 'c:\podata',            p_log  LIKE  rlgrap-filename DEFAULT 'c:\polog.xls'. SELECTION-SCREEN END OF BLOCK mod.  START-OF-SELECTION.   IF p_upload = 'X'.     PERFORM upload_file.     PERFORM upload_data.   ENDIF.   *&--------------------------------------------------------------------* *&      Form  upload_file *&--------------------------------------------------------------------* *       text *---------------------------------------------------------------------* FORM upload_file.    TRANSLATE p_file TO UPPER CASE.   len_str = STRLEN( p_file ).   len_str = len_str - 4.   IF p_file+len_str(4) <> '.XLS'.     CONCATENATE p_file '.XLS' INTO p_file.   ENDIF.   CALL FUNCTION 'KCD_EXCEL_OLE_TO_INT_CONVERT'     EXPORTING       filename                = p_file       i_begin_col             = 1       i_begin_row             = 2       i_end_col               = 256       i_end_row               = 65535     TABLES       intern                  = l_intern     EXCEPTIONS       inconsistent_parameters = 1       upload_ole              = 2       OTHERS                  = 3.   IF sy-subrc <> 0.   ENDIF.    SORT l_intern BY row col.   LOOP AT l_intern.     MOVE l_intern-col TO l_index.     ASSIGN COMPONENT l_index OF STRUCTURE it_data TO .     MOVE l_intern-value TO .     AT END OF row.       APPEND it_data.       CLEAR  it_data.     ENDAT.   ENDLOOP.  ENDFORM.                    "UPLOAD_FILE *&---------------------------------------------------------------------* *&      Form  UPLOAD_DATA *&---------------------------------------------------------------------* FORM upload_data .   CLEAR:it_head,it_item.   LOOP AT it_data.     MOVE-CORRESPONDING it_data TO it_head.     it_head-COLLECT_NO = it_data-po.     COLLECT it_head.     MOVE-CORRESPONDING it_data TO it_item.     APPEND  it_item.   ENDLOOP.   REFRESH it_msg.     LOOP AT it_head.     CLEAR: it_potexth,wa_pohead,wa_poheadx,wa_poaddrvendor.     REFRESH:it_potexth,it_popartner. *Document Type     wa_pohead-doc_type = 'NB'.     wa_poheadx-doc_type = 'X'.  *Vendor Number     CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'       EXPORTING         input  = it_head-vendor       IMPORTING         output = it_head-vendor.     wa_pohead-vendor = it_head-vendor.     wa_poheadx-vendor = 'X'. *Document Date     wa_pohead-doc_date = it_head-doc_date.     wa_poheadx-doc_date = 'X'.  *Collective Number     wa_pohead-COLLECT_NO = it_head-COLLECT_NO.     wa_poheadx-COLLECT_NO = 'X'.  *Company Code       wa_pohead-comp_code = '8200'.       wa_poheadx-comp_code = 'X'.   *Purchase Organise       wa_pohead-purch_org = '8200'.  *Purchase Group       wa_pohead-pur_group = '003'.       wa_poheadx-pur_group = 'X'.  *Payment term       wa_pohead-pmnttrms = it_head-pmnttrms.       wa_poheadx-pmnttrms = 'X'.  *Currency     wa_pohead-currency = it_head-currency.     wa_poheadx-currency = 'X'.  *Purchase Order Header Text       it_potexth-text_line = it_data-remark.    "Header Remark(Header Text)       it_potexth-po_number = it_head-po_number.       it_potexth-text_id   = 'F01'.       APPEND it_potexth.       CLEAR it_potexth.  *SHIPPING INSTRUCTION     it_potexth-text_line = it_head-shippingin.  "Ship Date(Header Text)     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F02'.     APPEND it_potexth.     CLEAR it_potexth. *PAYMENT TERM FOR PRP     it_potexth-text_line = it_data-load_date.  "Load Date(Header Text)     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F03'.     APPEND it_potexth.     CLEAR it_potexth. *Date of ETA HK     it_potexth-text_line = it_data-eta_hk.    "Date of ETA HK     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F04'.     APPEND it_potexth.     CLEAR it_potexth. *Date of Arr HK     it_potexth-text_line = it_data-arr_hk.    "Date of Arr HK     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F05'.     APPEND it_potexth.     CLEAR it_potexth.  *Transpotion Method     it_potexth-text_line = it_data-trsp_metd.     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F06'.     APPEND it_potexth.     CLEAR it_potexth.  *Container Number     it_potexth-text_line = it_data-container_no.     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F07'.     APPEND it_potexth.     CLEAR it_potexth.  *LC Number     it_potexth-text_line = it_data-lc_number.     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F08'.     APPEND it_potexth.     CLEAR it_potexth.  *Invoice Number     it_potexth-text_line = it_data-invoice_no.     it_potexth-po_number = it_head-po_number.     it_potexth-text_id   = 'F09'.     APPEND it_potexth.     CLEAR it_potexth.   *Purchase Order Item Information     CLEAR g_poitem.     REFRESH: it_poitemx,it_poitem,it_pocond,it_pocondx,              it_poche,it_pochex .      LOOP AT it_item.       IF  it_item-po EQ it_head-po.         CLEAR:it_poitem, it_poitemx.         g_poitem = g_poitem + 10.         it_poitem-po_item = g_poitem.         it_poitemx-po_item = g_poitem.         it_poitem-item_cat = it_item-item_cat.         it_poitemx-item_cat = 'X'.         it_poitemx-po_itemx = 'X'.         CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'           EXPORTING             input  = it_item-material           IMPORTING             output = it_item-material.          it_poitem-material = it_item-material.         it_poitemx-material = 'X'.         IF it_item-short_text IS NOT INITIAL.           it_poitem-short_text = it_item-short_text.           it_poitemx-short_text = 'X'.          ENDIF.          CLEAR g_meng.         g_meng = it_item-quantity.         it_poitem-quantity = g_meng.         it_poitemx-quantity = 'X'.         it_poitem-po_unit =  it_item-po_unit.         it_poitemx-po_unit =  'X'.          CLEAR g_mtart.         SELECT SINGLE mtart INTO g_mtart FROM mara                 WHERE matnr EQ it_item-material.         IF g_mtart EQ 'ZNON'.           it_poitem-acctasscat = 'Z'.           it_poitemx-acctasscat = 'X'.         ENDIF.           CLEAR:  it_poche,it_pochex.         it_poche-po_item   = g_poitem.         it_pochex-po_item  = g_poitem.         it_poche-sched_line   = g_poitem.         it_pochex-sched_line  = g_poitem.         it_poche-delivery_date  = it_item-gr_to_date.         it_pochex-delivery_date  = 'X'.          it_poche-quantity   = g_meng.         it_pochex-quantity  = 'X'.          it_pochex-po_itemx = 'X'.         it_pochex-sched_linex = 'X'.           APPEND: it_poche,it_pochex.          it_poitem-plant = '8200'.         it_poitemx-plant = 'X'.         IF it_item-matl_group IS NOT INITIAL.           it_poitem-matl_group = it_item-matl_group.           it_poitemx-matl_group = 'X'.         ENDIF.         it_poitem-over_dlv_tol = it_item-over_dlv_tol.         it_poitemx-over_dlv_tol = 'X'.         it_poitem-tax_code = it_item-tax_code.         it_poitemx-tax_code = 'X'.         g_menge = it_item-cond_pb00.          IF g_menge EQ  0.           it_poitem-free_item = 'X'.           it_poitemx-free_item = 'X'.         ELSE.           it_poitem-free_item = ''.           it_poitemx-free_item = 'X'.         ENDIF.          it_poitem-matl_group = it_item-matl_group.         it_poitemx-matl_group = 'X'.           IT_POITEM-NET_PRICE = IT_ITEM-COND_PB00.         IT_POITEMX-NET_PRICE = 'X'.         it_poitem-price_unit = it_item-cond_p_unt.         it_poitemx-price_unit = 'X'.         APPEND:it_poitemx,it_poitem.   *ConditionS         CLEAR it_pocond.         it_pocond-cond_type = 'PB00'.         it_pocond-itm_number = it_poitem-po_item.         it_pocond-cond_value = IT_ITEM-COND_PB00.         it_pocond-cond_p_unt  =  it_item-cond_p_unt.         it_pocond-currency    = it_head-currency.         it_pocond-change_id   = 'U'.         APPEND it_pocond.          CLEAR it_pocondx.         it_pocondx-cond_type = 'X'.         it_pocondx-itm_number = it_poitem-po_item.         it_pocondx-cond_value = 'X'.         it_pocondx-cond_p_unt = 'X'.         it_pocondx-currency    = 'X'.         it_pocondx-change_id   = 'X'.         APPEND it_pocondx.        ENDIF.     ENDLOOP.      wa_testrun = p_flag.     DELETE it_item WHERE  po EQ it_head-po.     SELECT SINGLE ebeln INTO g_ebeln FROM ekko         WHERE ebeln EQ wa_pohead-po_number.     IF sy-subrc NE 0.        REFRESH: it_poitem,it_poitemx,it_poche,it_pochex,              it_pocond,it_pocondx,it_potexth,it_potexti,it_popartner.     CLEAR:it_return,it_poitem,it_poitemx,it_poche,it_pochex,              it_pocond,it_pocondx,it_potexth,it_potexti,it_popartner.     DELETE it_item WHERE po EQ it_head-po.     DELETE it_head WHERE po EQ it_head-po. *    LOOP AT it_return WHERE type EQ 'E'.     LOOP AT it_return.       MOVE-CORRESPONDING it_return TO it_msg1. *      it_msg1-ebeln = wa_pohead-po_number.       it_msg1-ebeln = purchseorder.       it_msg1-old_po = it_head-po.       APPEND it_msg1.       clear it_msg1.     ENDLOOP.     ENDIF.    ENDLOOP.     CALL FUNCTION 'WS_DOWNLOAD'     EXPORTING       filename                = p_log       filetype                = 'DAT'       mode                    = 'O'     TABLES       data_tab                = it_msg1     EXCEPTIONS       invalid_filesize        = 1       invalid_table_width     = 2       invalid_type            = 3       no_batch                = 4       unknown_error           = 5       gui_refuse_filetransfer = 6       OTHERS                  = 7.   IF sy-subrc <> 0.     MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno             WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.   ENDIF.  ENDFORM.                    " UPLOAD_DATA 

四， 最后说的是使用ALE技术， 利用IDOC和BAPI实现数据传输功能。我在这里提供一个链接，这是郭裕老师的在线课程录像下载， 主要讲述的是ALE技术和MASTER DATA DISTRIBUTION技术：http://www.itpub.net/494989,1.html