Union all is the only set operator allowed between the last anchor member and first recursive member , and when combining multiple recursive members 在最后一个定位点成员和第一个递归成员之间,以及组合多个递归成员时,只能使用union all集合运算符。
The transact - sql union set operator can be used within a view to combine the results of two or more queries from separate tables into a single result set Transact - sql union集合运算符可在视图内使用,将单独表的两个或多个查询的结果组合到单一的结果集中。