SQL Query inserting data into database - asp.net

Question

I am trying to insert date into database from Session DateValue by converting it into dateTime. The problem i am facing is its accepting the value of april month but when i am entering the value of March its giving error.
Please Help, The Query and the code i have used is as follow:
string a = Session["Date_Value"].ToString();
DateTime date= DateTime.Parse(a);
foreach (GridViewRow g1 in grdData.Rows)
{
//string Status = (g1.FindControl("TextBox1") as TextBox).Text;
//int Status = Convert.ToInt32(Sta);
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Real_Attendance"].ConnectionString);
SqlCommand cmd = new SqlCommand("Insert into Attendanc(Stu_id,Status,time,Date,Sub_id) values('" + g1.Cells[3].Text + "',#Status,'" + Session["Time_Value"].ToString() + "', #Date ,'" + Session["Sub_id"].ToString() + "')", con);
//SqlCommand cmd = new SqlCommand("Insert into Attendanc(Stu_id,Status,time,Date,Sub_id) values('" + g1.Cells[3].Text + "','"+ g1.Cells[1].Text +"','" + Session["Time_Value"].ToString() + "','" + Session["Date_Value"].ToString() + "','" + Session["Sub_id"].ToString() + "')", con);
//cmd.Parameters["#Status"].Value = ((Label)(g1.FindControl("Label1"))).Text;
cmd.Parameters.AddWithValue("#Status", ((Label)(g1.FindControl("Label1"))).Text);
cmd.Parameters.AddWithValue("#Date", date.ToShortDateString());
// cmd.Parameters.AddWithValue("#Date", date.ToShortDateString());
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
This is the code I am using to create session. I am creating session at webform3 And using its value at webform4
protected void Calendar1_SelectionChanged(object sender, EventArgs e)
{
Calendar1.Visible = false;
System.DateTime myDate = new System.DateTime();
myDate = Calendar1.SelectedDate;
txtDate.Text = myDate.ToString("dd/MM/yyyy");
Date = txtDate.Text;
day = Calendar1.SelectedDate.DayOfWeek.ToString();
Response.Write(day);
txtday.Text = day;
Session["Date_Value"] = Date;
//SelectTime();
}

Answer 1

I'm not sure this will solve your problem, but it will improve your code:
string a = Session["Date_Value"].ToString();
DateTime date= DateTime.Parse(a);
using(SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Real_Attendance"].ConnectionString))
{
con.Open();
foreach (GridViewRow g1 in grdData.Rows)
{
using(SqlCommand cmd = new SqlCommand("Insert into Attendanc (Stu_id,Status,time,Date,Sub_id) values (#Stu_id, #Status, #Time, Convert(DateTime, #Date, 103), #Sub_id)", con))
{
cmd.Parameters.AddWithValue("#Stu_id", g1.Cells[3].Text);
cmd.Parameters.AddWithValue("#Status", ((Label)(g1.FindControl("Label1"))).Text);
cmd.Parameters.AddWithValue("#Time", Session["Time_Value"].ToString());
cmd.Parameters.AddWithValue("#Date", date.ToString("dd/MM/yyyy"));
cmd.Parameters.AddWithValue("#Sub_id", Session["Sub_id"].ToString());
cmd.ExecuteNonQuery();
}
}
con.Close();
}
First, I've changed sql statement to have only parameters. It's cleaner, safer, and easier to read and debug this way.
Second, I've changed the value that #Date parameter gets to a specific date format, and informed the database the expected format using the Convert function. this should fix your conversion problem.
Other improvements: I've moved the opening and closing of the connection outside of the foreach loop. there is no need to close and reopen the connection for each command execute. Also, I've moved the SqlConnection and the SqlCommand into using statements, as recommended by microsoft.