What does this mean in refid Mybatis

1, first define a sql tag, be sure to define a unique id 

      Example: <SQL ID = "Base_Column_List"> name, Age </ SQL>
2, and referenced by the ID
<SELECT ID = "a selectAll">
 SELECT
   <include the refid = "Base_Column_List" />
 from Student
</ SELECT>
this <include refid = "Base_Column_List" /> automatically over the above code stickers 

This blog post from: https: //blog.csdn.net/lzh578903779/article/details/71158323/