Question

如果在SQL Server 2014中运行以下查询，您会得到DT列的结果？它应该是“1”，但在SQL Server 2008中，我得到“0”。

SELECT
    CASE WHEN CAST('2014-01-02 00:00:00.001' AS DATETIME) > CAST('2014-01-02 00:00:00.000' AS DATETIME) THEN 1 ELSE 0 END AS 'DT'
    , CASE WHEN CAST('2014-01-02 00:00:00.002' AS DATETIME) > CAST('2014-01-02 00:00:00.000' AS DATETIME) THEN 1 ELSE 0 END AS 'DT2'
    , CASE WHEN '2014-01-02 00:00:00.001' > '2014-01-02 00:00:00.000' THEN 1 ELSE 0 END AS 'VARCHAR'

Answer 1

日期时间字段的分辨率为 3个小数位。只能在3.33毫秒内准确

SQL Server将'2014-01-02 00:00:00.001'和'2014-01-02 00:00:00.000'都视为2014-01-02 00:00:00.000。

SELECT Cast('2014-01-02 00:00:00.001' AS DATETIME),
       Cast('2014-01-02 00:00:00.000' AS DATETIME)

两个日期的结果相同。

在你的案例陈述中CAST('2014-01-02 00:00:00.001' AS DATETIME) > CAST('2014-01-02 00:00:00.000' AS DATETIME)失败了，因为两者都是相同的，所以其他部分0都有效。

确认SQL Server错误？

1 个答案: