sql转换日期转换错误的原因是什么?

I'm using the following code:

我使用的代码如下:

sqlcom.CommandText = "SELECT * FROM myTable"
                    + " WHERE CAST(myTime AS DATE) >= CAST(@mySTime AS DATE)"
                    + " AND CAST(myTime AS DATE) <= CAST(@myETime AS DATE)"
                    + "order by myTime ";

sqlcom.Parameters.AddWithValue("@mySTime", stime);
sqlcom.Parameters.AddWithValue("@myETime", etime);
sql