完全指定但未使用辅助键时发出警告，但如果指定则出错
Warning when secondary key fully specified but not used, but if specified then error
我很困惑。如果我编译下面这段代码
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
Program ZZY
Secondary key "SEC_KEY" is completely specified. However, the primary
key is used for access. Check whether access using "SEC_KEY" is more
efficient
但是如果我用 USING KEY sec_key 指定这个键，那么我会得到一个编译时错误！
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( ).
Program ZZY
Key "SEC_KEY" is a secondary key of type "HASHED KEY". All key components must be provided in these cases
我做错了什么？
如 syntax documentation of the LOOP conditions、
中所述
If a secondary table key is specified, any WHERE condition also specified must be optimizable. Otherwise a syntax error occurs or an exception is raised.
在深入研究可比较和可优化的规则以及不可比较和可优化的规则时，请确保手边有足够的咖啡或任何您喜欢的兴奋剂，因为那是乏味的事情。在这种情况下，指定的比较必须包括一个 TYPE P 和一个 TYPE C（如 '100.00'）——这应该是可能的——但另外，长度必须匹配，但它们不匹配吨。甚至文档也指出
Due to the complexity of the comparison rules (particularly for elementary data types, it is not a good idea to construct a set of rules detailing exactly when the comparison type matches the data type of the left operand.
底线：对密钥访问使用完全相同的类型，永远不要依赖隐式转换。如果您使用与 valueN 列相同的类型声明一个变量或常量并在比较中使用它，它就有效。
我很困惑。如果我编译下面这段代码
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
Program ZZY
Secondary key "SEC_KEY" is completely specified. However, the primary
key is used for access. Check whether access using "SEC_KEY" is more
efficient
但是如果我用 USING KEY sec_key 指定这个键，那么我会得到一个编译时错误！
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( ).
Program ZZY
Key "SEC_KEY" is a secondary key of type "HASHED KEY". All key components must be provided in these cases
我做错了什么？
如 syntax documentation of the LOOP conditions、
If a secondary table key is specified, any WHERE condition also specified must be optimizable. Otherwise a syntax error occurs or an exception is raised.
在深入研究可比较和可优化的规则以及不可比较和可优化的规则时，请确保手边有足够的咖啡或任何您喜欢的兴奋剂，因为那是乏味的事情。在这种情况下，指定的比较必须包括一个 TYPE P 和一个 TYPE C（如 '100.00'）——这应该是可能的——但另外，长度必须匹配，但它们不匹配吨。甚至文档也指出
Due to the complexity of the comparison rules (particularly for elementary data types, it is not a good idea to construct a set of rules detailing exactly when the comparison type matches the data type of the left operand.
底线：对密钥访问使用完全相同的类型，永远不要依赖隐式转换。如果您使用与 valueN 列相同的类型声明一个变量或常量并在比较中使用它，它就有效。