Question

我很困惑。如果我编译下面的代码

REPORT zzy.

CLASS lcl_main DEFINITION FINAL CREATE PRIVATE.
  PUBLIC SECTION.
    CLASS-METHODS:
      class_constructor,
      main.
  PRIVATE SECTION.
    TYPES: BEGIN OF t_record,
      transid TYPE sy-index,
      item1   TYPE char20,
      value1  TYPE p LENGTH 7 DECIMALS 2,
      value2  TYPE p LENGTH 7 DECIMALS 2,
      value3  TYPE p LENGTH 7 DECIMALS 2,
      value4  TYPE p LENGTH 7 DECIMALS 2,
    END OF t_record,
    tt_record TYPE STANDARD TABLE OF t_record WITH NON-UNIQUE KEY transid item1 WITH UNIQUE HASHED KEY sec_key COMPONENTS value1 value2 value3.
    CLASS-DATA:
      mt_record TYPE tt_record.
ENDCLASS.

CLASS lcl_main IMPLEMENTATION.
  METHOD class_constructor.
    DO 10 TIMES.
      INSERT VALUE t_record( transid = sy-index item1 = |Item{ sy-index }| value1 = sy-index value2 = sy-index / 2 value3 = sy-index / 4 value4 = 0 )
        INTO TABLE mt_record.
    ENDDO.
  ENDMETHOD.

  METHOD main.
    DATA:
      l_secs TYPE i,
      l_millisecs TYPE i,
      l_start TYPE timestampl,
      l_end   TYPE timestampl,
      l_diff  LIKE l_start.
    GET TIME STAMP FIELD l_start.
    LOOP AT mt_record INTO DATA(ls_record)
      WHERE value1 = '100.00' AND value2 = '150.0' AND value3 = '10.0'.

      ASSERT 1 = 1.

    ENDLOOP.
    GET TIME STAMP FIELD l_end.
    l_diff = l_end - l_start.

    WRITE: / l_diff.
  ENDMETHOD.
ENDCLASS.

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

我收到以下警告

程序ZZY
辅助密钥“SEC_KEY”已完全指定。但是，主要的 key用于访问。检查使用“SEC_KEY”的访问是否更多高效

但如果我用USING KEY sec_key指定此密钥，那么我会收到编译时错误！

REPORT zzy.

CLASS lcl_main DEFINITION FINAL CREATE PRIVATE.
  PUBLIC SECTION.
    CLASS-METHODS:
      class_constructor,
      main.
  PRIVATE SECTION.
    TYPES: BEGIN OF t_record,
      transid TYPE sy-index,
      item1   TYPE char20,
      value1  TYPE p LENGTH 7 DECIMALS 2,
      value2  TYPE p LENGTH 7 DECIMALS 2,
      value3  TYPE p LENGTH 7 DECIMALS 2,
      value4  TYPE p LENGTH 7 DECIMALS 2,
    END OF t_record,
    tt_record TYPE STANDARD TABLE OF t_record WITH NON-UNIQUE KEY transid item1 WITH UNIQUE HASHED KEY sec_key COMPONENTS value1 value2 value3.
    CLASS-DATA:
      mt_record TYPE tt_record.
ENDCLASS.

CLASS lcl_main IMPLEMENTATION.
  METHOD class_constructor.
    DO 10 TIMES.
      INSERT VALUE t_record( transid = sy-index item1 = |Item{ sy-index }| value1 = sy-index value2 = sy-index / 2 value3 = sy-index / 4 value4 = 0 )
        INTO TABLE mt_record.
    ENDDO.
  ENDMETHOD.

  METHOD main.
    DATA:
      l_secs TYPE i,
      l_millisecs TYPE i,
      l_start TYPE timestampl,
      l_end   TYPE timestampl,
      l_diff  LIKE l_start.
    GET TIME STAMP FIELD l_start.
    LOOP AT mt_record INTO DATA(ls_record) USING KEY sec_key
      WHERE value1 = '100.00' AND value2 = '150.0' AND value3 = '10.0'.

      ASSERT 1 = 1.

    ENDLOOP.
    GET TIME STAMP FIELD l_end.
    l_diff = l_end - l_start.

    WRITE: / l_diff.
  ENDMETHOD.
ENDCLASS.

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

程序ZZY
键“SEC_KEY”是“HASHED KEY”类型的辅助键。在这些情况下必须提供所有关键组件

我在这里做错了什么？

Answer 1

如syntax documentation of the LOOP conditions中所述，

如果指定了辅助表键，则指定的任何WHERE条件都必须为optimizable。否则会发生语法错误或引发异常。

当你深入了解可比较和优化的规则时，一定要有足够的咖啡或任何你喜欢的兴奋剂供应，因为这是繁琐的事情。在这种情况下，指定的比较必须包含TYPE P和TYPE C（如'100.00'） - 这应该是可能的 - 但此外，长度必须匹配，他们不会吨。甚至文档都说明了

由于比较规则的复杂性（特别是对于基本数据类型，构建一组规则时，详细说明比较类型何时匹配左操作数的数据类型并不是一个好主意。

底线：使用完全相同的类型进行密钥访问，从不依赖隐式转换。如果使用与valueN列相同的类型声明变量或常量，并在比较中使用它，则可以正常工作。

完全指定但未使用辅助密钥时发出警告，但如果指定则错误

1 个答案: