Created by Wang, Jerry, last modified on May 10, 2017
struct2 = CORRESPONDING #( struct1 ). col2 and col3 of structure 2 will be overwritten by fields from structur1 可以看到虽然structu2的COL4不相关，但是也变空了。 解决方法就是 struct2 = CORRESPONDING #( BASE ( base ) struct1 ).
