收到错误＆＃39;多次指定列＆＃39;用union all sql查询

Question

这是我的疑问：

select * from (
    select Name, Address
    from table1
    UNION ALL
    select Name, Address
    from table2
) D

执行此查询时收到错误：

  

列＆＃39;名称＆＃39;被多次指定为＆＃39; D＆＃39;。

Answer 1

使用别名

select * from (
    select t1.Name, t1.Address
    from table1 as t1
    UNION ALL
    select t2.Name, t2.Address
    from table2 as t2
) D

Answer 2

select * from (
      select t1.Name as t1_Name, t1_Address as t1_Address
          from table t1
             UNION ALL
      select t2.Name as t2_Name, t2_Address as t2_Address
          from table t2
) D

试试这个