Changing a value to datetime c#

fred brass

I am trying to change a value selected in a drop down list to a datetime. The values bound to the drop down list are from a Date column under a datetime2 type, however they change when bound to the drop down list. When the date in the drop down list is selected it should populate a gridview according to the value, but because the format is changed the 'where' clause in my sql statement is invalid.

My code is as follows:

protected void DropDownList2_SelectedIndexChanged(object sener, EventArgs e)
{
String query = "SELECT Stock_Take.Username, Item.ItemID, Item.ItemDesc, Stock_Take_Item.BarQuantity, Stock_Take_Item.StorageQuantity, Stock_Take.StockTakeIDNew FROM Item INNER JOIN Stock_Take_Item ON Item.ItemID = Stock_Take_Item.ItemID INNER JOIN Stock_Take ON Stock_Take_Item.StockTakeIDNew = Stock_Take.StockTakeIDNew where Stock_Take.Username = @USER AND Stock_Take.StockDate = @DATE";
SqlConnection con = new SqlConnection(@"Data Source=(local)\;Initial Catalog=SmallBatch;Integrated Security=True;");
con.Open();
SqlCommand cmd = new SqlCommand(query, con);
DropDownList2.SelectedValue.GetType();
cmd.Parameters.Add("@USER", SqlDbType.VarChar).Value = DropDownList1.SelectedValue;
var date = DateTime.ParseExact(DropDownList2.SelectedValue, "yyyy/MM/dd hh:mm:ss", null);
cmd.Parameters.Add("@DATE", SqlDbType.DateTime).Value = date;
// DateTime date = Convert.ToDateTime(DropDownList2.SelectedValue.ToString());
SqlDataReader reader = cmd.ExecuteReader();
GridView1.DataSource = reader;
GridView1.DataBind();
con.Close();
}

An error is throwing on the line var date = DateTime.ParseExact 'String was not recognized as valid DateTime'

3 Replies

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Amit Gupta8y ago
I believe ParseExtract requires exact format of datetime that youi get into the dropdown.SelectedValue.

Just be assure what you are getting and what you are parsing.
Reshma Bhalekar8y ago
Hi,

Try to debug the code and check the value of DropDownList2.SelectedValue.

Check this links:

https://www.c-sharpcorner.com/UploadFile/70dbe6/string-was-not-recognized-as-a-valid-datetime-error-and-thei/

https://stackoverflow.com/questions/8401605/c-sharp-datetime-parseexact
Nitin Sontakke8y ago
I am not quite up-to-date with front-end technologies and you didn't mention whether this is web or Windows forms application.

In any case, I believe, that the dropdown will be capable of storing two values for each entry, one is "DisplayMember" and another is "ValueMember". I suggest you keep whatever you want to show in display member and the real date in yyyy-MM-dd format in Value member.