ABAP S4 新语法 sql with 的用法demo

REPORT demo_cte.

CLASS demo DEFINITION.
  PUBLIC SECTION.
    TYPES: BEGIN OF struct,
             carrname TYPE scarr-carrname,
             connid   TYPE spfli-connid,
             cityfrom TYPE spfli-cityfrom,
             cityto   TYPE spfli-cityto,
             cnt      TYPE int8,
           END OF struct.
    CLASS-DATA itab TYPE TABLE OF struct WITH EMPTY KEY.
    CLASS-METHODS main.
ENDCLASS.

CLASS demo IMPLEMENTATION.
  METHOD main.
    DATA carrid TYPE spfli-carrid VALUE 'LH'.
    cl_demo_input=>request( CHANGING field = carrid ).
    carrid = to_upper( carrid ).

    WITH
      +conns AS (
        SELECT carrname, connid, cityfrom, cityto
              FROM spfli
                JOIN scarr ON spfli~carrid = scarr~carrid
              WHERE spfli~carrid = @carrid ),
      +cnts AS (
        SELECT COUNT(*) AS cnt
               FROM +conns )
      SELECT *
             FROM +cnts
               CROSS JOIN +conns
             ORDER BY carrname, connid
             INTO CORRESPONDING FIELDS of TABLE @itab.

    cl_demo_output=>display( itab ).
  ENDMETHOD.
ENDCLASS.

START-OF-SELECTION.
  demo=>main( ).

上图代码输出结果：

看到结果输出很容易理解代码需要实现的效果了。