验证CAST日期值是否大于另一个不起作用的CAST日期值

Question

我正在尝试检查我作为日期值转换的VARCHAR值，然后检查转换值是否大于另一个值是否按预期工作。

我附上了s.EFFECTIVE_DATE的图片，其大于t.StatusEffectiveDate以及为什么它会出现在我的结果集中。这是我的问题。

这是我的代码，如果问题出现在WHERE子句下面的粗体AND语句：

DECLARE @peims2016SnapshotDate date = '2016-10-28'
        SELECT t.StudentID, t.Status, s.status, t.StatusEffectiveDate, s.effective_date, t.enddate, @peims2016SnapshotDate as peimssnapshotdate, CONVERT(VARCHAR(10), DATEADD(day, -1, t.Enddate),101) as NewEndDate
        FROM Mcsfwisdtest.FRA.dbo.vw_HHSurvey s
        INNER JOIN Fwisddw.dbo.Focus_Export_Econ_DisadvantagedHHS_TEST t
        ON s.CustomerID = t.StudentID
        AND s.SiteID = LocationID
        WHERE CAST(t.Enddate as date) > @peims2016SnapshotDate 
        **AND CAST(s.effective_date as date) > CAST(t.StatusEffectiveDate as date)**
        AND t.[Status] = 'PAID' AND s.[Status] != 'PAID' 
        OR (t.[Status] = 'REDUCED' AND s.[Status] = 'FREE')
        ORDER BY t.StudentID asc

Answer 1

您需要使用正确的样式（在您的情况下为样式date）转换为101：

DECLARE @peims2016SnapshotDate date = '2016-10-28'

SELECT  t.StudentID, 
        t.Status, 
        s.status, 
        t.StatusEffectiveDate, 
        s.effective_date, 
        t.enddate, 
        @peims2016SnapshotDate as peimssnapshotdate, 
        CONVERT(VARCHAR(10),DATEADD(DAY,-1,t.Enddate),101) as NewEndDate
FROM Mcsfwisdtest.FRA.dbo.vw_HHSurvey s
INNER JOIN Fwisddw.dbo.Focus_Export_Econ_DisadvantagedHHS_TEST t
    ON s.CustomerID = t.StudentID
    AND s.SiteID = LocationID
WHERE CAST(t.Enddate as date) > @peims2016SnapshotDate 
AND CONVERT(date,s.effective_date,101) > CONVERT(date,t.StatusEffectiveDate,101)
AND ((t.[Status] = 'PAID' AND s.[Status] != 'PAID') 
OR (t.[Status] = 'REDUCED' AND s.[Status] = 'FREE'))
ORDER BY t.StudentID asc;