how to show table value according to selection of dropdownlist

Question

2.00/5 (1 vote)

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Textbox is showing Quantity after submit button1 click.I want Quantity on selection of dropdownlist.code is.......
protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
{

con.Open();
SqlCommand cmd1 = new SqlCommand("SELECT Quantity from AddedItem where Item_Name='" + DropDownList3.SelectedItem.Text + "'", con);
SqlDataReader dr = cmd1.ExecuteReader(CommandBehavior.SingleRow);
if (dr.Read())
{
TextBox3.Text = dr.GetValue(0).ToString();
dr.Close();
}

}

protected void Button1_Click(object sender, EventArgs e)
{
string st = "";

if (IsPostBack)
{
try
{

SqlCommand cmd1 = new SqlCommand("SELECT Item_Id from AddedItem where Item_Name='" + DropDownList3.SelectedItem.Text + "'", con);
SqlDataReader dr = cmd1.ExecuteReader(CommandBehavior.SingleRow);
if (dr.Read())
{

st = dr[0].ToString();
dr.Close();
}
SqlCommand cmd = new SqlCommand("INSERT INTO IssuedItem VALUES('" + st + "','" + DropDownList1.SelectedItem.Text + "','" + DropDownList2.SelectedItem.Text + "','"+DropDownList3.SelectedItem.Text+"','"+Calendar1.SelectedDate.ToShortDateString()+"','"+TextBox2.Text+"')", con);

cmd.ExecuteNonQuery();
}
catch (SqlException ex)
{

}
finally
{
con.Close();

}
}

}

Posted 15-Nov-11 18:14pm

Member 7909353

Updated 16-Nov-11 18:32pm

v4

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Comments

[no name] 16-Nov-11 0:17am

Format code snippets

[no name] 16-Nov-11 0:19am

What textbox? What do you mean "is not working"?

Zubair Alie 16-Nov-11 0:49am

code is fine.
may you have any quantity stored at index 0 if datarow. you can check it in (AddWatch) that what value you are receiving in dr[0].toString();

3 solutions

Solution 2

Let's see:

There is no such event as DropDownList3_SelectedIndexChanged. Nothing tells me that this method was actually added as an event handler to the event DropDownList3.SelectedIndexChanged. Check it up.
Using names like DropDownList3, SelectedIndexChangedDropDownList3_SelectedIndexChanged is invitation to trouble and violation of good Microsoft naming conventions. Yes, they were generated by Microsoft Designer, but who told you that you're supposed to keep them? Give all members some semantic names, always.
Don't open and close connection every time. Best of all, open it on demand using lazy evaluation pattern, http://en.wikipedia.org/wiki/Lazy_evaluation[^].
Why do you assume that a single row should be returned by SqlDataReader. Also, you don't have any provision to empty result of the query; in this case dr[0] may throw index-out-of-range exception.
Don't use string concatenation, at least not repeatedly. This is because string type is immutable. Do I have to explain why? In your case, use string.Format instead.
Run the code under debugger to see what's going on.

—SA

Posted 15-Nov-11 18:34pm

Sergey Alexandrovich Kryukov

Updated 15-Nov-11 18:35pm

v2

Comments

Zubair Alie 16-Nov-11 0:40am

Hi SAKryukov,
You are pointing out right things but the way you are pointing out it may disappoint or pressurize member. because may he is at a student level now.
treat him in the way he asked a question

hope you understand

Thanks :)

Solution 3

USE THE FOLLOWING CODE.

TextBox3.Text = dr.GetValue[0];

Posted 15-Nov-11 18:41pm

Dipak V Nakum

Comments

Zubair Alie 16-Nov-11 0:54am

dr.GetValue[0] => Java Property
dr[0].toString() => .Net Property (C#)

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ujjwal uniyal · Accepted Answer · 2011-11-15T18:21:00

Solution 1

use dr.getvalue(0).Tostring(); insted of dr[0].Tostring()

Posted 15-Nov-11 18:21pm

ujjwal uniyal

Comments

Zubair Alie 16-Nov-11 0:54am

dr.GetValue[0] => Java Property
dr[0].toString() => .Net Property (C#)

ujjwal uniyal 16-Nov-11 1:16am

had it not been the property it wouldn't have been provided in the intelisence . use it, it works just the way u want it to work.