How To Fix WL130 - Table action "Append" not possible when reading an element

SAP Error Message - Details

• Message type: E = Error

• Message class: WL - Workflow: run-time messages

• Message number: 130

• Message text: Table action "Append" not possible when reading an element

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Smart SAP Assistant

• What is the cause and solution for SAP error message WL130 - Table action "Append" not possible when reading an element ?

  The SAP error message WL130, which states "Table action 'Append' not possible when reading an element," typically occurs in the context of working with internal tables in ABAP (Advanced Business Application Programming). This error indicates that there is an attempt to append data to an internal table while it is in a read mode, which is not allowed.
  Cause:
  The error can occur due to several reasons:
  
  Read Mode: The internal table is being accessed in a read mode (e.g., using a LOOP statement) when an attempt is made to append data to it.
  Incorrect Logic: The logic in the program may be structured in such a way that it tries to modify the internal table while it is being read.
  Nested Loops: If you have nested loops and you are trying to append to the inner loop's internal table while iterating over it, this can trigger the error.
  
  Solution:
  To resolve the WL130 error, consider the following solutions:
  
  
  Separate Read and Write Operations: Ensure that you separate the read and write operations. For example, if you are looping through an internal table, do not attempt to append to that table within the loop. Instead, collect the data you want to append in a separate internal table and append it after the loop.
  DATA: lt_source TYPE TABLE OF your_table_type,
        lt_append TYPE TABLE OF your_table_type,
        ls_new_row TYPE your_table_type.
  
  LOOP AT lt_source INTO DATA(ls_row).
    " Process your data
    " Collect new rows to append
    APPEND ls_new_row TO lt_append.
  ENDLOOP.
  
  " Now append the collected rows to the original table
  APPEND LINES OF lt_append TO lt_source.
  
  
  Use Temporary Tables: If you need to modify the table while reading it, consider using a temporary table to store the new entries and then append them to the original table after the read operation is complete.
  
  
  Check Loop Logic: Review your loop logic to ensure that you are not inadvertently trying to modify the table you are currently iterating over.
  
  
  Debugging: Use debugging tools to step through your code and identify where the append operation is being called during a read operation.
  
  
  Related Information:
  
  ABAP Documentation: Refer to the official SAP ABAP documentation for more details on internal tables and their operations.
  SAP Community: Engage with the SAP Community forums for discussions and solutions related to similar issues.
  Error Handling: Implement error handling in your ABAP code to gracefully manage situations where such errors might occur.
  
  By following these guidelines, you should be able to resolve the WL130 error and ensure that your ABAP code functions correctly without attempting to append to an internal table while it is being read.