无法对System.String和System.DateTime执行'>'操作

Question

I'm trying to filter my DataView by date:

DataTable dt = GetTableData();
DataView dvEvents = dt.DefaultView;
dvEvents.RowFilter = "date > #" + DateTime.Now.ToString() + "#";

But I'm getting this error:

Cannot perform '>' operation on System.String and System.DateTime.

I've also tried DateTime.Now.ToString("MM/dd/yyyy") , and I get the same error.

What am I doing wrong here?

Answer 1

If you are using string values you need to replace the # with ' .

For example:

dvEvents.RowFilter = "date > '" + DateTime.Now.ToString() + "'";

See this reference

Answer 2

It looks like date is defined as a string. You have two options.

You can either make sure string is stored in yyyyMMdd format (so that sorting and filtering works properly) and filter such as:

 dvEvents.RowFilter = "date > '" + DateTime.Now.ToString("yyyyMMdd") + "'";

OR you can turn date into actual DateTime column and keep you current code

Answer 3

如果日期来自数据库，则必须在进行比较之前进行区域设置转换。

Answer 4

I had a similar issue and none of the already suggested resolutions worked. A work around was to use

DataTable dt = GetTableData();
DataView dvEvents = dt.DefaultView;
dvEvents.RowFilter = "date > '" + DateTime.Now.ToString("MM/dd/YYYY") + "'";

Hope this helps someone.