How To Fix 37191 - Use at least two loop blocks when selecting

SAP Error Message - Details

• Message type: E = Error

• Message class: 37 - Screen Painter

• Message number: 191

• Message text: Use at least two loop blocks when selecting

What causes this issue?

You are defining or maintaining a step loop and have chosen <LS>Sel.
loop block end</>.
You must define the position and size of the loop block as a
rectangular screen area. One corner of the loop block was already fixed
and the opposing corner is determined by the cursor position.
In most cases, you define loop blocks as one-line loop blocks, but the
rectangular area is a special case since it is part of a line.
The system first attempts to create a minimal step loop from two loop
block repetitions. However, there is not enough free space for this
below the defined loop block.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Place the cursor so that you define a loop block which has space for
two repetitions and repeat the function.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 37191 - Use at least two loop blocks when selecting ?

  The SAP error message 37191 ("Use at least two loop blocks when selecting") typically occurs in ABAP programming when you are trying to perform a SELECT statement that requires the use of nested loops but you have not defined them correctly. This error is often encountered when working with internal tables and trying to process data in a way that requires multiple iterations.
  Cause:
  The error arises when:
  
  You are attempting to select data from a database table and process it in a nested manner (e.g., using a loop inside another loop) but have not structured your code to include at least two loop blocks.
  The logic of your program expects to handle multiple sets of data, but the way the loops are defined does not meet the requirement for nested processing.
  
  Solution:
  To resolve this error, you need to ensure that your ABAP code includes at least two loop blocks when performing the selection. Here’s a general approach to fix the issue:
  
  
  Check Your Loops: Review your code to ensure that you have defined at least two nested loops. For example, if you are processing data from two related tables, you should have a loop for the outer table and another loop for the inner table.
  
  
  Example Code:
  Here’s a simple example of how to structure your loops correctly:
  DATA: lt_table1 TYPE TABLE OF your_table1,
        lt_table2 TYPE TABLE OF your_table2,
        ls_table1  TYPE your_table1,
        ls_table2  TYPE your_table2.
  
  SELECT * FROM your_table1 INTO TABLE lt_table1.
  SELECT * FROM your_table2 INTO TABLE lt_table2.
  
  LOOP AT lt_table1 INTO ls_table1.
    " Process each entry in table1
    LOOP AT lt_table2 INTO ls_table2.
      " Process each entry in table2 related to the current entry in table1
      " Your processing logic here
    ENDLOOP.
  ENDLOOP.
  
  
  Review Logic: Ensure that the logic of your program requires the nested loops. If you only need to process a single table, you may not need nested loops at all.
  
  
  Debugging: If you are unsure where the error is occurring, use debugging tools in the ABAP Workbench to step through your code and identify where the loop structure is not meeting the requirements.
  
  
  Related Information:
  
  ABAP Documentation: Refer to the official SAP documentation for more details on loop constructs and SELECT statements in ABAP.
  Performance Considerations: Be mindful of performance when using nested loops, especially with large datasets. Consider using JOINs in your SELECT statements if applicable, to reduce the need for nested loops.
  Best Practices: Always ensure that your code is structured clearly and logically to avoid confusion and potential errors.
  
  By following these guidelines, you should be able to resolve the error message 37191 and improve the structure of your ABAP code.