Question

c# 两个datetimepicker 控件，怎么写查询数据库的sql语言

我这样写了，为什么不对？？
DateTime dt1= Convert.ToDateTime(DateTimePicker1.Value);
DateTime dt2=Convert.ToDateTime(DateTimePicker2.Value);
selectString="select * from table1 where [time] between dt1 and dt2";
其中time是日期/时间属性。
string query = "select * from table1 where time between '" + dateTimePicker1.Value.ToString("yyyy/MM/dd HH:mm;ss") + "' and '" + dateTimePicker2.Value.ToString("yyyy/MM/dd HH:mm;ss") + "'";
这样写也不对

Answer 1

string query = "select * from table1 where time between '" + dateTimePicker1.Value.ToString("yyyy/MM/dd HH:mm;ss") + "' and '" + dateTimePicker2.Value.ToString("yyyy/MM/dd HH:mm;ss") + "'";

PS:上面写法当然不对，between和and只能用于基本类型，比如说int等。
要进行时间比较，应该用数据库服务器提供的时间比较函数，比如说SQL Server中的
timediff()，详细用法请参考SQL Server用户手册。

追问

string time1 = dateTimePicker1.Value.ToString("yyyy/MM/dd HH:mm:ss");
string time2 = dateTimePicker2.Value.ToString("yyyy/MM/dd HH:mm:ss");

string query = "select * from table1 where time between #" + time1 + "# and #" + time2 + "#";
经过我的摸索，这样写可以。经过试验，可以达到目的。