S4语法整理

1. VALUE type( ... )，DATA(WA)

临时定义类型并且赋值给构造

  TYPES:
    BEGIN OF TY_TAB,
     ZCHAR1 TYPE C LENGTH 10,
     ZCHAR2 TYPE C LENGTH 10,
     ZCHAR3 TYPE C LENGTH 10,
     ZCHAR4 TYPE C LENGTH 10,
    END OF TY_TAB.


  DATA(WA) = VALUE TY_TAB( ZCHAR1 = '1' ZCHAR2 = '2' ZCHAR3 = '3' ZCHAR4 = '4' ).

  CL_DEMO_OUTPUT=>DISPLAY( WA ).

表赋值

  DATA:
    LT_TAB TYPE TT_TAB.

  LT_TAB = VALUE #( ( ZCHAR1 = '1' ZCHAR2 = '1' ZCHAR3 = '3' ZCHAR4 = '4' )
                    ( ZCHAR1 = '1' ZCHAR2 = '1' ZCHAR3 = '3' ZCHAR4 = '4' )
                    ( ZCHAR1 = '1' ZCHAR2 = '1' ZCHAR3 = '3' ZCHAR4 = '4' )
                    ( ZCHAR1 = '1' ZCHAR2 = '1' ZCHAR3 = '3' ZCHAR4 = '4' )
                    ZCHAR1 = '1' ( ZCHAR2 = '2' ZCHAR3 = '6' ZCHAR4 = '6' )
                                 ( ZCHAR2 = '2' ZCHAR3 = '7' ZCHAR4 = '7' )
                    ZCHAR1 = '1' ZCHAR2 = '3' ( ZCHAR3 = '6' ZCHAR4 = '6' )
                                              ( ZCHAR3 = '7' ZCHAR4 = '7' )
                    ZCHAR1 = '1' ZCHAR2 = '4' ( ZCHAR3 = '6' ZCHAR4 = '6' )
                                              ( ZCHAR3 = '7' ZCHAR4 = '7' )

                  ).

  CL_DEMO_OUTPUT=>DISPLAY( LT_TAB ).

测试发现 括号的变量可以变少，但是不能变少之后再变多

内表追加数据

 

内表操作指定行赋值(不会改变系统变量SY-TABIX的值)

  DATA(WA1) = LT_TAB[ 5 ].

  CL_DEMO_OUTPUT=>DISPLAY( WA1 ).

字符拼接

指针:

  ASSIGN COMPONENT L_I OF STRUCTURE WA1 TO FIELD-SYMBOL(<FS_TS>).
  
  ASSIGN LT_TAB[ 5 ] TO FIELD-SYMBOL(<FS>).

  READ TABLE LT_TAB ASSIGNING FIELD-SYMBOL(<FS_READ>) WITH  KEY ZCHAR1 = '3'.

内表数据读取(读取不到会抛异常，所以以下两种方法执行避免一种DUMP)

  TRY .
    DATA(WA3) = LT_TAB1[ ZCHAR1 = '1'  ].

  CATCH CX_SY_ITAB_LINE_NOT_FOUND INTO DATA(oref)  .

    DATA(STR11) = oref->GET_TEXT( ).

    WRITE:/ STR11.
  ENDTRY.


  IF line_exists( LT_TAB1[ ZCHAR1 = '1'  ] ).

    DATA(WA2) = LT_TAB1[ ZCHAR1 = '1'  ].

  ENDIF.

1.MOVE-CORRESPONDING

表或者字段之间相同字段赋值

*  MOVE-CORRESPONDING LT_TAB TO LT_TAB1.

  LT_TAB1 = CORRESPONDING #( LT_TAB ).

  CL_DEMO_OUTPUT=>DISPLAY( LT_TAB1 ).

2.FOR 写法及相关应用

TYPES:
  BEGIN OF LINE,
    COL1 TYPE I,
    COL2 TYPE I,
    COL3 TYPE I,
  END OF LINE,

  ITAB TYPE STANDARD TABLE OF LINE WITH EMPTY KEY.

  DATA(ITAB) = VALUE ITAB(

    FOR J = 11 THEN J * 10 UNTIL J > 4000
      ( COL1 = J COL2 = J + 1 COL3 = J + 2 )

   ).

*  返回一个值
  DATA(TOTAL) = REDUCE I( INIT RES = 0 FOR WA IN ITAB WHERE ( COL1 < 1000 ) NEXT  RES = RES + WA-COL1 ).

* 返回一个结构
  DATA(RESULT) = REDUCE LINE( INIT RES1 = VALUE LINE( COL2 = 0 COL3 = 9999999 )

                FOR WA IN ITAB WHERE ( COL1 IS NOT INITIAL )
                NEXT RES1-COL1 = RES1-COL1 + 1
                     RES1-COL2 = NMAX( VAL1 = RES1-COL1 VAL2 = WA-COL2  )
                     RES1-COL3 = NMIN( VAL1 = RES1-COL1 VAL2 = WA-COL3  )
   ).


  CL_DEMO_OUTPUT=>DISPLAY( ITAB ).


  CL_DEMO_OUTPUT=>DISPLAY( TOTAL ).

  CL_DEMO_OUTPUT=>DISPLAY( RESULT ).

内表中满足条件的数据放到另一内表

  DATA(ITAB2) = VALUE ITAB( FOR WA IN ITAB WHERE ( COL1 < 1000 )

                  (  COL1 = WA-COL1   COL2 = WA-COL2  COL3 = WA-COL3 )
     ).

   CL_DEMO_OUTPUT=>DISPLAY( ITAB2 ).

LOOP GROUP BY

  TYPES:
    BEGIN OF TY_LINE,
      C1 TYPE C LENGTH 20,
      C2 TYPE C LENGTH 20,
      C3 TYPE C LENGTH 20,
      C4 TYPE I ,
    END OF TY_LINE,

    ITAB TYPE STANDARD TABLE OF TY_LINE WITH EMPTY KEY.

  DATA(ITAB) = VALUE ITAB(
       C1 = 'A' ( C2 = 'A' C3 = 'A' C4 = 1 )
                ( C2 = 'B' C3 = 'B' C4 = 2 )
                ( C2 = 'C' C3 = 'C' C4 = 3 )
       C1 = 'B' ( C2 = 'A' C3 = 'A' C4 = 1 )
                ( C2 = 'B' C3 = 'B' C4 = 2 )
                ( C2 = 'C' C3 = 'C' C4 = 3 )
       C1 = 'C' ( C2 = 'A' C3 = 'A' C4 = 1 )
                ( C2 = 'B' C3 = 'B' C4 = 2 )
                ( C2 = 'C' C3 = 'C' C4 = 3 )
    ) .


  DATA(ITAB3) = VALUE ITAB( ).

  LOOP AT ITAB INTO DATA(WA) GROUP BY WA-C1.

    DATA(ITAB1) = VALUE ITAB( ).

    LOOP AT GROUP WA INTO DATA(WA1).  "遍历分组后得结果机


       ITAB1  = VALUE ITAB( BASE ITAB1 ( WA1 ) ).  "将结果集追加进表 BASE得用法

    ENDLOOP.

*   对分组后得数据进行累加
    DATA(SUM) = REDUCE I( INIT RES = 0 FOR WA2 IN ITAB1

                               NEXT RES = RES + WA2-C4
                      ) .

    IF ITAB1 IS NOT INITIAL.
      DATA(LS_ITAB) = ITAB1[ 1 ].

      LS_ITAB-C4 = SUM.

      ITAB3 = VALUE ITAB( BASE ITAB3 ( LS_ITAB ) ).
    ENDIF.


  ENDLOOP.

  CL_DEMO_OUTPUT=>DISPLAY( ITAB3 ).

自定义分组

  DATA(MEMBERS) = VALUE ITAB( ).
  
  LOOP AT ITAB ASSIGNING FIELD-SYMBOL(<FS_AB>)
    GROUP BY COND  STRING(
        WHEN <FS_AB>-C1 = 'A' THEN |START|
        WHEN <FS_AB>-C1 = 'B' THEN |MIDDLE|
        ELSE |END|
        )
    INTO DATA(GROUP).

    IF GROUP = 'START'.
      MEMBERS = VALUE #( FOR G1 IN GROUP GROUP ( G1 ) ).
    ENDIF.

  ENDLOOP.

  CL_DEMO_OUTPUT=>DISPLAY( MEMBERS ).

FILTER过滤器的试用(需要排序表或者哈希表)

EXCEPT如果不指定则表示满足条件的找出来，如果指定则表示不满足条件的找出来

  DATA(ITAB5) = FILTER ITAB1( ITBA4 IN MEMBERS1
                             WHERE C1 = C1
                         ).

  CL_DEMO_OUTPUT=>DISPLAY( ITAB5 ).
  DATA(ITAB6) = FILTER ITAB1( ITBA4
                             WHERE C1 = CONV #( 'C' )
                         ).

  CL_DEMO_OUTPUT=>DISPLAY( ITAB6 ).

 

S/4对象创建

    DATA(OREF) = NEW  CL_TOOLS_LOCAL( ).

     OREF->H_TOOLS_BT_DATES_001(


        EXPORTING U_BEGDA = '20181011' U_ENDDA = '20181101'

        IMPORTING E_DAY = DATA(L_DAY1)
     ).