SAP ABAP 通用取数函数

FUNCTION EXTRACT_TABLE_DATA.
*"----------------------------------------------------------------------
*"*"Local Interface:
*"  TABLES
*"      FIELDS STRUCTURE  ZSQL_CLAUSE_ELEMENTS
*"      FROMCLAUSE STRUCTURE  ZSQL_CLAUSE_ELEMENTS
*"      WHERECLAUSE STRUCTURE  ZSQL_CLAUSE_ELEMENTS
*"      DATA STRUCTURE  ZTABLEROWS
*"----------------------------------------------------------------------
*"----------------------------------------------------------------------
*" Copy selected fields from QUERY_TABLE to DATA_STRUCTURE
*"----------------------------------------------------------------------
  TYPE-POOLS: abap.
  DATA:
        columnName TYPE SO_TEXT, 
        fieldDataDescrRef  TYPE REF TO abap_componentdescr, 
        numberFields TYPE i, 
        fieldDescr TYPE abap_componentdescr, 
        fieldname TYPE string, 
        fieldDescrTab TYPE abap_component_tab,
        rowStructDescr TYPE REF TO cl_abap_structdescr, 
        rowReference TYPE REF TO data, 
        returnRowString TYPE string, 
        dataFieldString TYPE string, 
        dataline LIKE data, 
        fromClauseRow TYPE ZALBUS_STRUCT_WHERECLAUSE,
        fromClauseString TYPE string,
        whereClauseRow TYPE ZALBUS_STRUCT_WHERECLAUSE,
        whereClauseString TYPE string,
        fieldsRow TYPE ZALBUS_STRUCT_WHERECLAUSE.
  FIELD-SYMBOLS:
          <datarow> TYPE ANY, 
          <datafield> TYPE ANY. 
 
 
* CREATE DataStructure with field names 
* Datatypes are read from fieldnames of FIELDS input table
  DESCRIBE TABLE FIELDS LINES numberFields.
  LOOP AT FIELDS INTO fieldsRow.
    fieldname = SY-TABIX.
* names need to be unique and must start with a char
    CONCATENATE 'string' fieldname INTO fieldname.
    CONDENSE fieldname.
    fieldDescr-name = fieldname.
* for dictionary lookup we need to change columnnames from Open SQL
* to dictionary notation
    columnName = fieldsRow-TEXT.
    REPLACE FIRST OCCURRENCE OF SUBSTRING '~' IN columnName WITH '-' RESPECTING CASE.
 
    fieldDescr-type ?= cl_abap_typedescr=>describe_by_name( columnName ).
    APPEND fieldDescr TO fieldDescrTab.
  ENDLOOP.
 
  rowStructDescr = cl_abap_structdescr=>create( fieldDescrTab ).
 
* now we create the actual data structure in memory
  create data rowReference type HANDLE rowStructDescr.
* finally we assign it to the Field-symbol used by the select statement
  ASSIGN rowReference->* TO <datarow>.
* End Create DataStructure
 
* to simplify calls we concatenate from and whereclause into strings
* this way caller doesn't need to check word wrappings
  fromClauseString = ''.
  LOOP AT FROMCLAUSE INTO fromClauseRow.
    CONCATENATE fromClauseString fromClauseRow-TEXT INTO fromClauseString.
  ENDLOOP.
  whereClauseString = ''.
  LOOP AT WHERECLAUSE INTO whereClauseRow.
    CONCATENATE whereClauseString whereClauseRow-TEXT INTO whereClauseString.
  ENDLOOP.
* Now start actual select operation
  SELECT (FIELDS) FROM (fromClauseString) INTO <datarow> WHERE (whereClauseString).
* we read all fields of the current row, cast it to string and
* concatenate it into a dataline with division chars.
    CLEAR: returnRowString.
    DO numberFields TIMES.
      ASSIGN component sy-index of structure <datarow> to <datafield>.
      dataFieldString = <datafield>.
      CONCATENATE returnRowString '|' datafieldstring INTO returnRowString.
    ENDDO.
    dataline = returnRowString.
* finally dataline is added to the return table.
    INSERT dataline INTO TABLE data.
  ENDSELECT.
ENDFUNCTION.