Selection Screens — PARAMETERS and SELECT-OPTIONS

Why Selection Screens?

Every business report needs user input: "Show me sales orders from January to March for customer X." Selection screens are ABAP's built-in way to collect this input before the report runs.

When you run a report with F8, SAP displays the selection screen first. The user fills in parameters, clicks Execute, and the report processes data based on those inputs.

PARAMETERS — Single Value Input

REPORT z_selection_screen.

* Single input fields
PARAMETERS: p_cust  TYPE kunnr,                        " Customer number
            p_date  TYPE datum DEFAULT sy-datum,        " Date with default
            p_dept  TYPE c LENGTH 30 DEFAULT 'Engineering', " Text with default
            p_count TYPE i DEFAULT 100.                 " Number with default

START-OF-SELECTION.
  WRITE: / |Customer: { p_cust }|.
  WRITE: / |Date: { p_date }|.
  WRITE: / |Department: { p_dept }|.
  WRITE: / |Max rows: { p_count }|.

When you run this with F8, SAP shows a screen with four input fields. The user fills them in and clicks Execute (F8 again). Then the code after START-OF-SELECTION runs.

Parameter Options

PARAMETERS: p_name  TYPE string OBLIGATORY,             " Required field
            p_type  TYPE c LENGTH 2 DEFAULT 'TA',       " Default value
            p_check TYPE abap_bool AS CHECKBOX,          " Checkbox
            p_radio1 RADIOBUTTON GROUP grp1 DEFAULT 'X', " Radio button (selected)
            p_radio2 RADIOBUTTON GROUP grp1.             " Radio button (not selected)

• OBLIGATORY — user must fill this field (shows a checkmark)
• AS CHECKBOX — renders as a checkbox instead of an input field
• RADIOBUTTON GROUP — groups radio buttons (only one can be selected)

SELECT-OPTIONS — Range Input

SELECT-OPTIONS are more powerful than PARAMETERS — they accept ranges, patterns, and multiple values:

* Range input fields
SELECT-OPTIONS: s_kunnr FOR kna1-kunnr,     " Customer number range
                s_date  FOR sy-datum,        " Date range
                s_land  FOR kna1-land1.      " Country range

START-OF-SELECTION.
  * s_kunnr, s_date, s_land are RANGE tables (Lesson 17)
  SELECT kunnr, name1, land1
    FROM kna1
    INTO TABLE @DATA(lt_customers)
    WHERE kunnr IN @s_kunnr
      AND land1 IN @s_land.

  WRITE: / |Found { lines( lt_customers ) } customers|.
  LOOP AT lt_customers INTO DATA(ls_c).
    WRITE: / |{ ls_c-kunnr }: { ls_c-name1 } ({ ls_c-land1 })|.
  ENDLOOP.

The FOR keyword tells SAP which field the SELECT-OPTION is based on — it inherits the type, F4 help, and description from that field. The user can enter:

• A single value: 1001
• A range: 1001 to 1999
• Multiple values (click the multiple selection button)
• Exclusions (toggle Include/Exclude)

Internally, each SELECT-OPTION is a RANGE table — exactly what we learned in Lesson 17.

Screen Layout

Blocks

SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE TEXT-001.
  PARAMETERS: p_cust TYPE kunnr OBLIGATORY.
  SELECT-OPTIONS: s_date FOR sy-datum.
SELECTION-SCREEN END OF BLOCK b1.

SELECTION-SCREEN BEGIN OF BLOCK b2 WITH FRAME TITLE TEXT-002.
  PARAMETERS: p_count TYPE i DEFAULT 100.
  PARAMETERS: p_test AS CHECKBOX DEFAULT 'X'.
SELECTION-SCREEN END OF BLOCK b2.

TEXT-001 and TEXT-002 are text symbols — you define them via Goto → Text Elements → Text Symbols. For example, TEXT-001 = "Selection Criteria", TEXT-002 = "Output Options".

Comments and Spacing

SELECTION-SCREEN SKIP 1.               " Add a blank line
SELECTION-SCREEN COMMENT /1(60) TEXT-003.  " Add text comment
SELECTION-SCREEN ULINE.                " Add a horizontal line

Input Validation

AT SELECTION-SCREEN.
  * Validate customer exists
  IF p_cust IS NOT INITIAL.
    SELECT SINGLE kunnr FROM kna1 INTO @DATA(lv_check)
      WHERE kunnr = @p_cust.
    IF sy-subrc <> 0.
      MESSAGE |Customer { p_cust } does not exist| TYPE 'E'.
    ENDIF.
  ENDIF.

AT SELECTION-SCREEN ON s_date.
  * Validate date range
  LOOP AT s_date INTO DATA(ls_date).
    IF ls_date-low > sy-datum.
      MESSAGE 'Start date cannot be in the future' TYPE 'E'.
    ENDIF.
  ENDLOOP.

MESSAGE ... TYPE 'E' displays an error and returns the user to the selection screen. The event AT SELECTION-SCREEN fires when the user clicks Execute — before START-OF-SELECTION.

Setting Default Values at Runtime

INITIALIZATION.
  * Set defaults dynamically
  s_date-sign = 'I'.
  s_date-option = 'BT'.
  s_date-low = sy-datum - 30.   " 30 days ago
  s_date-high = sy-datum.        " Today
  APPEND s_date.

The INITIALIZATION event fires when the selection screen first appears — before the user sees it.

Key Takeaways

• PARAMETERS create single-value input fields. SELECT-OPTIONS create range inputs.
• SELECT-OPTIONS generate RANGE tables — use with WHERE field IN s_option in SELECT statements.
• OBLIGATORY makes a field required. AS CHECKBOX and RADIOBUTTON GROUP change the control type.
• Group related fields in SELECTION-SCREEN BLOCK for visual organization.
• Validate input in the AT SELECTION-SCREEN event — show errors before the report runs.
• Use INITIALIZATION to set dynamic defaults when the screen first appears.

Next Lesson

Selection screens collect input. But when does the actual processing happen? In Lesson 19: Events in ABAP Reports, we'll learn the event-driven execution model that controls the flow of every ABAP report.