Store compressed data in a table field

Question

Hi,
I would like to store in a field of a database a STRING that would have compressed before saving it in the DB. The string would be loaded from a text file on a file server. That's the reason why I want to compress it before I store it. I do not want to explode my disk space. I need to be able to decompress the field in SAP in order to display or read the content.
Question1: How can I compress/decompress a string?
Question2: What would be the type of the field in the database? RAW somthing?
Thank you,
Mike.

Answer 1

Hi Suresh
HERE IS THE CODE:
<b>COURTSEY:Durairaj Athavan Raja</b>
REPORT  y_store_xml.
DATA: wf_filetab TYPE filetable .
DATA: wf_filerc TYPE i ,
      wf_filename TYPE string ,
      wf_path TYPE string ,
      wf_full_path TYPE string ,
      wf_file_length TYPE i .
DATA: wf_extension TYPE string ,
      wf_fname TYPE string .
DATA: BEGIN OF int_tab1 OCCURS  0,
        int_txt(1000) TYPE x ,
      END OF int_tab1.
DATA: upd_tab TYPE STANDARD TABLE OF ytest_bin .
DATA: wa_upd_tab LIKE LINE OF upd_tab .
DATA: temp_xstring TYPE xstring .
DATA: NUM(2) TYPE C,
      LEN(7) TYPE I.
PARAMETERS: p_file LIKE file_table-filename LOWER CASE  VISIBLE LENGTH
80  .
AT SELECTION-SCREEN ON VALUE-REQUEST FOR p_file .
  PERFORM browse_file CHANGING p_file .
AT SELECTION-SCREEN ON p_file .
  IF p_file IS INITIAL .
    MESSAGE e398(00) WITH
       'Enter Filename and path' .
  ENDIF.
START-OF-SELECTION .
  CLEAR wf_filename .
  MOVE: p_file TO wf_filename .
  PERFORM load_file USING wf_filename .
  PERFORM save_file_contents .
*&      Form  browse_file
*       text
*      <--P_P_FILE  text
FORM browse_file  CHANGING p_p_file.
  CLEAR wf_filename .
  CALL METHOD cl_gui_frontend_services=>file_open_dialog
    EXPORTING
      window_title            = 'Select the File'
*    DEFAULT_EXTENSION       = cl_gui_frontend_services=>FILETYPE_TEXT
*    DEFAULT_FILENAME        =
*     FILE_FILTER             = cl_gui_frontend_services=>FILETYPE_EXCEL
*    INITIAL_DIRECTORY       =
*    MULTISELECTION          =
    CHANGING
      file_table              = wf_filetab
      rc                      = wf_filerc
*    USER_ACTION             =
    EXCEPTIONS
      file_open_dialog_failed = 1
      cntl_error              = 2
      error_no_gui            = 3
      not_supported_by_gui    = 4
      OTHERS                  = 5
  IF sy-subrc <> 0.
    MESSAGE e398(00) WITH 'Error Opening File' .
  ELSE .
    READ TABLE wf_filetab INDEX 1 INTO p_file .
  ENDIF.
ENDFORM.                    " browse_file
*&      Form  load_file
*       text
*      -->P_WF_FILENAME  text
FORM load_file  USING    p_wf_filename.
  CLEAR int_tab1 .
  REFRESH int_tab1 .
  CALL FUNCTION 'GUI_UPLOAD'
    EXPORTING
      filename                      = p_wf_filename
      filetype                      = 'BIN'
      CODEPAGE                      = 'UTF-16BE'
IMPORTING
   filelength                    = wf_file_length
*   HEADER                        =
    TABLES
      data_tab                      = int_tab1
   EXCEPTIONS
     file_open_error               = 1
     file_read_error               = 2
     no_batch                      = 3
     gui_refuse_filetransfer       = 4
     invalid_type                  = 5
     no_authority                  = 6
     unknown_error                 = 7
     bad_data_format               = 8
     header_not_allowed            = 9
     separator_not_allowed         = 10
     header_too_long               = 11
     unknown_dp_error              = 12
     access_denied                 = 13
     dp_out_of_memory              = 14
     disk_full                     = 15
     dp_timeout                    = 16
     OTHERS                        = 17
  IF sy-subrc <> 0.
    MESSAGE e398(00) WITH 'File may be open - Error loading' .
  ENDIF.
ENDFORM.                    " load_file
*&      Form  save_file_contents
*       text
*  -->  p1        text
*  <--  p2        text
FORM save_file_contents .
  CLEAR :wa_upd_tab , temp_xstring .
LOOP AT int_tab1 .
CONCATENATE temp_xstring int_tab1-int_txt  INTO temp_xstring IN BYTE
MODE.
  ENDLOOP .
  IF NOT temp_xstring IS INITIAL .
******* optional
    TRY.
        CALL METHOD cl_abap_gzip=>compress_binary
          EXPORTING
            raw_in   = temp_xstring
          IMPORTING
            gzip_out = wa_upd_tab-description.
      CATCH cx_parameter_invalid_range .
      CATCH cx_sy_buffer_overflow .
      CATCH cx_sy_compression_error .
    ENDTRY.
     SELECT MAX( DISTINCT KEY1 ) FROM YTEST_BIN INTO NUM.
     NUM = NUM + 1.
     wa_upd_tab-KEY1 = NUM.
     APPEND wa_upd_tab TO upd_tab .
  ENDIF .
  IF NOT upd_tab IS INITIAL .
    MODIFY ytest_bin FROM TABLE upd_tab .
    IF sy-subrc EQ 0 .
      MESSAGE i398(00) WITH wf_filename ` Saved!`.
    ENDIF .
  ENDIF.
*Same way try to DeCompress
CLEAR temp_xstring.
CLEAR  wa_upd_tab-description.
SELECT single * from ytest_bin into wa_upd_tab WHERE KEY1 EQ NUM.
CALL METHOD cl_abap_gzip=>DECOMPRESS_BINARY
EXPORTING
            gzip_in   = wa_upd_tab-description
          IMPORTING
            raw_out = temp_xstring
            RAW_OUT_LEN = len.
ENDFORM.                    " save_file_contents
CHEERS,
VIJAY RAHEJA