怎么对UNION ALL后的结果集进行查询

如何对UNION ALL后的结果集进行查询？

SQL code

SELECT                 SUBSTRING(REGDATE,1,4) + '-' + SUBSTRING(REGDATE,5,2) + '-' + SUBSTRING(REGDATE,7,2) as [日期],                 SUBSTRING(REGDATE,9,2) + ':' + SUBSTRING(REGDATE,11,2) as [时间],                N'入库指示' as [文件类型],                YYVBELN as [出货单编号],                YYINVNO as [发票编号],                YYEBELN as [PO编号],                REGDATE as [登录日]                from IN_STOCK_HEADER WHERE REGDATE like '%20111212%'                UNION ALL                --出库指示                SELECT                 SUBSTRING(REGDATE,1,4) + '-' + SUBSTRING(REGDATE,5,2) + '-' + SUBSTRING(REGDATE,7,2) as [日期],                 SUBSTRING(REGDATE,9,2) + ':' + SUBSTRING(REGDATE,11,2) as [时间],                N'出库指示' as [文件类型],                VBELN as [出货单编号],                '' as [发票编号],                '' as [PO编号],                REGDATE as [登录日]                from OUT_STOCK_HEADER

SQL code

select  *from  (SELECT                 SUBSTRING(REGDATE,1,4) + '-' + SUBSTRING(REGDATE,5,2) + '-' + SUBSTRING(REGDATE,7,2) as [日期],                 SUBSTRING(REGDATE,9,2) + ':' + SUBSTRING(REGDATE,11,2) as [时间],                N'入库指示' as [文件类型],                YYVBELN as [出货单编号],                YYINVNO as [发票编号],                YYEBELN as [PO编号],                REGDATE as [登录日]                from IN_STOCK_HEADER WHERE REGDATE like '%20111212%'                UNION ALL                --出库指示                SELECT                 SUBSTRING(REGDATE,1,4) + '-' + SUBSTRING(REGDATE,5,2) + '-' + SUBSTRING(REGDATE,7,2) as [日期],                 SUBSTRING(REGDATE,9,2) + ':' + SUBSTRING(REGDATE,11,2) as [时间],                N'出库指示' as [文件类型],                VBELN as [出货单编号],                '' as [发票编号],                '' as [PO编号],                REGDATE as [登录日]                from OUT_STOCK_HEADER)twhere  ....
[解决办法]
把你的查询括起来组成派生表
select * from (你的查询语句) as t where ....
as t不能漏掉，派生表需要别名