您不能将整数值直接转换为日期，但可以先将其转换为日期时间，然后再转换为日期类型

You can't convert an integer value straight to a date but you can first it to a datetime then to a date type

select cast(40835 as datetime)

然后转换为日期(SQL 2008)

and then convert to a date (SQL 2008)

select cast(cast(40835 as datetime) as date)

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