ALTER Procedure [dbo].[proc_Test](
    @StartTime datetime = NULL,
    @EndTime      datetime = NULL
)
AS 
exec('SELECT  
        *
    FROM
        Test T
    WHERE
        ('+@StartTime+' 
            is NULL or DATEDIFF(day,'+@StartTime+', T.CreateTime) >= 0) and
        ( '+@EndTime+' is NULL or DATEDIFF(day,'+@EndTime+', T.CreateTime) <= 0) 
    ORDER BY
        ID ')

ALTER Procedure [dbo].[proc_Test](
    @StartTime datetime = NULL,
    @EndTime      datetime = NULL
)
AS 
exec('SELECT  
        *
    FROM
        Test T
    WHERE
        ('+@StartTime+' 
            is NULL or DATEDIFF(day,'+convert(varchar(19),@StartTime,120)+', T.CreateTime) >= 0) and
        ( '+convert(varchar(19),@EndTime,120)+' is NULL or DATEDIFF(day,'+convert(varchar(19),@EndTime,120)+', T.CreateTime) <= 0) 
    ORDER BY
        ID ')

------解决方案--------------------
这个没必要动态执行,还有你检查一下是否都能转成日期呀,提示很明显

------解决方案--------------------
SQL code
exec('SELECT  
        *
    FROM
        Test T
    WHERE
        ('+@StartTime+' 
            is NULL or DATEDIFF(day,'+cast(@StartTime as varchar(50))+', T.CreateTime) >= 0) and
        ( '+@EndTime+' is NULL or DATEDIFF(day,'+@EndTime+', T.CreateTime) <= 0) 
    ORDER BY
        ID ')

------解决方案--------------------
SQL code
SELECT  
        *
    FROM
        Test T
    WHERE
        @StartTime
            is NULL or DATEDIFF(day,@StartTime, T.CreateTime) >= 0) and
        @EndTime is NULL or DATEDIFF(day,@EndTime, T.CreateTime) <= 0) 
    ORDER BY
        ID )

------解决方案--------------------
SQL code

'SELECT  
        *
    FROM
        Test T
    WHERE
        ('+CONVERT(NVARCHAR,@StartTime,111)+' 
            is NULL or DATEDIFF(day,'+CONVERT(NVARCHAR,@StartTime,111)+', T.CreateTime) >= 0) and
        ( '+CONVERT(NVARCHAR,@EndTime,111)+' is NULL or DATEDIFF(day,'+CONVERT(NVARCHAR,@EndTime,111)+', T.CreateTime) <= 0) 
    ORDER BY
        ID '

------解决方案--------------------
SQL code
SELECT  
        *
    FROM
        Test T
    WHERE
        @StartTime
            is NULL or DATEDIFF(day,@StartTime, T.CreateTime) >= 0) and
        @EndTime is NULL or DATEDIFF(day,@EndTime, T.CreateTime) <= 0) 
    ORDER BY
        ID