mssql 2012如何显示特定值

Question

我有查询

SELECT DATEDIFF(day,
                    CONVERT(char(10), GetDate(),101),
                    CONVERT(char(10), fieldname,101))
from tablename
where  isdate(fieldname)=1

查询的输出是

我怎么能只从结果???中显示6的值

Answer 1

SELECT DATEDIFF(day, CONVERT(char(10), GetDate(),101), CONVERT(char(10), fieldname,101))
FROM lablename
WHERE isdate(fieldname)=1
AND DATEDIFF(day, CONVERT(char(10), GetDate(),101), CONVERT(char(10), fieldname,101)) = 6

编辑1

SELECT * FROM 
(    SELECT DATEDIFF(day, CONVERT(char(10), GetDate(),101), CONVERT(char(10), fieldname,101)) AS DateDiff
    FROM lablename
    WHERE isdate(fieldname)=1
) A 
WHERE DateDiff = 6