将日期参数从C＃WinForm传递到SQL存储过程

Question

I have a form with 2 dateTimePicker controls ( dtpStart and dtpEnd ), a button, and a datagridview to show results. The datagridview is bound to a bindingSource control.

I want to pass two date parameters from the dateTimePicker controls to the stored procedure in order to return the required scope on my datagridview.

My stored procedure looks like this:

CREATE PROC [dbo].[ProcTest](@StartDate date, @EndDate date)
AS
SELECT * FROM Test WHERE ModifiedDate BETWEEN @StartDate AND @EndDate

My C# code is:

    private void button1_Click(object sender, EventArgs e)
    {
        dc = new NorthwindDataContext();

        var Qry = dc.ProcTest(dtpStart.Value, dtpEnd.Value);
        bindingSource1.DataSource = Qry;
    }

When I run the code above I receive nothing on my datagrid, the dtpEnd.value shows: 13/08/2012 02:15:29 , I assume that this is a conversion issue since I use date type in my stored procedure and the datetimepicker value is a dateTime type.

Please, how to resolve this ?

Answer 1

You need to retrieve the results of your query, eg:

bindingSource1.DataSource = Qry.ToList();

I don't think the issue is with the Date parameter at all. That's supported according to:

http://msdn.microsoft.com/en-us/library/bb386947.aspx

Answer 2

Instead of this

var Qry = dc.ProcTest(dtpStart.Value, dtpEnd.Value);

use this and check if your problem get solved.

var Qry = dc.ProcTest(dtpStart.ToString("dd-MMM-yyyy"), dtpEnd.ToString("dd-MMM-yyyy"));

Answer 3

Thanks to the link provided by Dave R.: http://msdn.microsoft.com/en-us/library/bb386947.aspx I found out that my code could work without any modification. So I searched the error first by removing parameters from SP, then I found that I had to create a new datasource object pointing to the result of the SP , and to bind it at design time to the datagridview. Now the datagrid shows data and parameters are working.

Sorry Guys, I had to verify that before posting my question, but I was very confused about Date parameters usage.

so I Keep the code as it is in the initial question:

private void button1_Click(object sender, EventArgs e)
{
    dc = new NorthwindDataContext();

    var Qry = dc.ProcTest(dtpStart.Value, dtpEnd.Value);
    bindingSource1.DataSource = Qry;
}

Answer 4

I beleive you need to send the date, not the value of your datetime picker.

Basically, change this line:

var Qry = dc.ProcTest(dtpStart.Value, dtpEnd.Value);

To read:

var Qry = dc.ProcTest(dtpStart.SelectedDate.Value, dtpEnd.SelectedDate.Value);

If that still doesn't work I would try:

var Qry = dc.ProcTest(dtpStart.SelectedDate.Value.Date, dtpEnd.SelectedDate.Value.Date);