Dump in field symbol assigen

Question

Hi ,
i try to do this statement and i have dump
BEGIN OF tt_agr ,
        agr_name TYPE agr_name,
        text TYPE agr_title,
       END OF tt_agr .
FIELD-SYMBOLS: <ls_retr_txt1> TYPE tt_agr.
LOOP AT lt_help ASSIGNING <ls_help_value>.
    SPLIT <ls_help_value> AT space INTO ls_agr-agr_name ls_agr-text.
    SHIFT ls_agr-text LEFT DELETING LEADING space.
    READ TABLE It_retr_roles ASSIGNING <ls_retr_txt1> WITH KEY agr_name = ls_agr-agr_name.
    IF sy-subrc = 0.
      <ls_retr_txt1>-text = ls_agr-text . "<- here the dump occuer
    ENDIF.
  ENDLOOP.
this is the dump analysis what i miss here ?
Error analysis
    A new value is to be assigned to the field "<LS_RETR_TXT1>", although this
     field is
    entirely or partly protected against changes.
    The following are protected from change:
    - Character literals or numerical literals.
    - CONSTANTS.
    - Parameters of the category IMPORTING REFERENCE in functions and
      methods.
    - untyped field symbols, that have not been assigned a field using
      ASSIGN.
    - TABLES parameters, if the actual parameter is protected against
      changes.
    - USING reference parameters and CHANGING parameters in FORMs,
      if the actual parameter is protected against changes.
    - Access using field symbols if the field assigned using ASSIGN is
      partly or completely protected (for example key components of internal
      table of the type SORTED or HASHED TABLE).
    - Access using field symbols if the field assigned using ASSIGN contains
      components of a secondary key that is currently in use in a
      higher-level LOOP statement.
    - Access using references if the field bound to the reference is
      (partly) protected against changes.
    - Write access from outside to READ-ONLY attributes.
    - Content of a shared objects area instance accessed using a shared lock
      (ATTACH_FOR_READ.
    - Rows or fields of a table that are currently being serialized by a
      Simple Transformation.
Regards
Joy

Answer 1

Hi,
if It_retr_roles is defined as CHANGING (which is against naming rules, should be Ct_retr_roles), then the table is defined as SORTED OR HASHED and field TEXT is part of the key. Key fields may never be changed.
You may build a new local internal table and replace the original at end of method.
Regards,
Clemens