基础查数据
问题举例：例如查物料类型为ZFRT、ZROH和ZRSA的物料编码。
1、直接查询，三种不同类型的物料类型是或的关系。
SELECT DISTINCT ma~matnr ma~mtart
FROM mara AS ma
INNER JOIN mbewh AS mb
ON ma~matnr = mb~matnr
INTO CORRESPONDING FIELDS OF TABLE gt_tab
WHERE ma~mtart EQ 'ZFRT' OR
ma~mtart EQ 'ZROH' OR
ma~mtart EQ 'ZRSA'.2、如果对1进行优化，三种物料类型放在列表项中，使用关键字IN，这样查询等价于1.
SELECT DISTINCT ma~matnr ma~mtart
FROM mara AS ma
INNER JOIN mbewh AS mb
ON ma~matnr = mb~matnr
INTO CORRESPONDING FIELDS OF TABLE gt_tab
WHERE ma~mtart IN ( 'ZFRT' , 'ZROH', 'ZRSA' ).3、定义区间函数，RANGE 内表
https://www.cnblogs.com/buduzhiren/p/13131483.html
SAP ABAP编程 Ranges用法_m15188153014的博客-CSDN博客
定义区间结构：
TYPES: BEGIN OF ty_sign,
sign TYPE sign,
option TYPE option,
low TYPE mtart,
high TYPE mtart,
END OF ty_sign. "定义区间结构
（1）直接赋值，不建议这种直接堆叠赋值方式，代码量比较多。
DATA: lt_mtart TYPE TABLE OF ty_sign WITH HEADER LINE. "定义区间表
lt_mtart-sign = 'I'. "赋值
lt_mtart-option = 'EQ'.
lt_mtart-low = 'ZFRT'.
APPEND lt_mtart TO lt_mtart.
lt_mtart-sign = 'I'.
lt_mtart-option = 'EQ'.
lt_mtart-low = 'ZROH'.
APPEND lt_mtart TO lt_mtart.
lt_mtart-sign = 'I'.
lt_mtart-option = 'EQ'.
lt_mtart-low = 'ZRSA'.
APPEND lt_mtart TO lt_mtart.
CLEAR lt_mtart.
(2) 优化：使用VALUE#() 进行赋值，建议这种方式，代码量会大大减少。
DATA: lt_mtart TYPE TABLE OF ty_sign .
lt_mtart = VALUE #( sign = 'I' option = 'EQ' ( low = 'ZFRT' high = '' )
( low = 'ZROH' high = '' )
( low = 'ZRSA' high = '' )
).（3）或者用APPEND VALUE#() TO ITAB. 与（2）二者等同。
DATA: lt_mtart TYPE TABLE OF ty_sign .
APPEND VALUE #( sign = 'I' option = 'EQ' low = 'ZFRT' high = '' ) TO lt_mtart.
APPEND VALUE #( sign = 'I' option = 'EQ' low = 'ZROH' high = '' ) TO lt_mtart.
APPEND VALUE #( sign = 'I' option = 'EQ' low = 'ZRSA' high = '' ) TO lt_mtart.
对RANGE内表 赋值完成后的，以上三种方式的查询语句均相同。
SELECT DISTINCT ma~matnr ma~mtart
FROM mara AS ma
INNER JOIN mbewh AS mb
ON ma~matnr = mb~matnr
INTO CORRESPONDING FIELDS OF TABLE gt_tab
WHERE ma~mtart IN lt_mtart.总结： 1、如果是多个字符，使用第二种，IN +列表项，查询最为简洁；
2、如果有多个区间，可以使用VALUE#()方式进行赋值。
