how to use for loop with inset query

Question

0.00/5 (No votes)

See more:

C#

int count = Convert.ToInt16(ddlvehicles.SelectedValue);
           for (int i = 2; i <= count; i++)
           {
               cmd.Parameters.Clear();
               cmd.CommandText = "usp_booking_insert";
               cmd.CommandType = CommandType.StoredProcedure;
               cmd.Parameters.AddWithValue("@user_id", ddluname.SelectedValue);
               cmd.Parameters.AddWithValue("@journey_place", txtjplace.Text);
               cmd.Parameters.AddWithValue("@pickup_date", txtpickup_daterri.Text);
               cmd.Parameters.AddWithValue("@pickup_address", txtpickup_address.Text);
               cmd.Parameters.AddWithValue("@return_date", txtreturndate.Text);
               cmd.Parameters.AddWithValue("@return_address", txtreturn_address.Text);
               cmd.Parameters.AddWithValue("@service_id", ddlsname.SelectedValue);
               cmd.Parameters.AddWithValue("@vehicle_id", ddlvehicles.SelectedValue);
               cmd.Parameters.AddWithValue("@vtype_ac_nonac", ddlvtype1.SelectedValue);
               cmd.Parameters.AddWithValue("@vrate_km_day", ddlrate1.SelectedValue);
               cmd.Parameters.AddWithValue("@mode_of_payment", rdbtnpayment.SelectedItem.ToString());
               int vid = Convert.ToInt16(((DropDownList)mvbooking.Views[0].FindControl("ddlvehicles1" + i+1)).SelectedValue);
               string vtype = ((DropDownList)mvbooking.Views[0].FindControl("ddlvtype1" + i+1)).SelectedValue;
               string vrate = ((DropDownList)mvbooking.Views[0].FindControl("ddlvrate1" + i+1)).SelectedValue;

dis is my insert query. bt i want to add vehicle upto they are selected. i tried using for loop like dis.. but it is not working there is an error of "Object reference not set to an instance of an object." in "int vid=...;" line

help me plz

Posted 19-Mar-13 7:38am

Member 9671810

Add a Solution

Comments

ZurdoDev 19-Mar-13 13:57pm

So, you need to find out how to get access to ddlvehicles1i.

mhd.sbt 19-Mar-13 13:58pm

hi buddy
can i see your complete code?
i mean,asax file that related to this page
and page or class that contain this page

Jegan Thiyagesan 19-Mar-13 15:46pm

Are you sure you should be looking for control ("ddlvehicles1" + i+1)?
shouldn't this be ("ddlvehicles" + i+1), without the number at the end, because you are adding the number using the for loop.
if i = 0;
("ddlvehicles1" + i+1) = "ddlvehicles11" and
("ddlvehicles" + i+1) = "ddlvehicles1".

Member 9671810 20-Mar-13 12:15pm

yup..
but the thing was that i was not knowing how to start my loop as my ddl values stares from 2 or more..
i mean when i used dis loop to display panel it worked so hoped that this will also work..
and i have ddlvehicle1 upto ddlvehicle10.
but anyways i solved..

"Thanx for your co-operation"

2 solutions

Solution 1

First of all, read this: 3 common causes of system nullreferenceexception (object reference not set to an instance of an object)[^]

Second, if you use:

C#

int count = Convert.ToInt16(ddlvehicles.SelectedValue);

how can you excepect that below code will execute correctly, especially when i is bigger then count?

C#

string vtype = ((DropDownList)mvbooking.Views[0].FindControl("ddlvtype1" + i+1)).SelectedValue;

Third, you want to convert i + 1 to string expression. Try to use: Int32.ToString Method[^] or Convert.ToString method[^].

Posted 19-Mar-13 8:11am

Maciej Los

Comments

fjdiewornncalwe 19-Mar-13 15:47pm

5.

Maciej Los 19-Mar-13 15:51pm

Thank you, Marcus ;)

Jegan Thiyagesan 20-Mar-13 8:06am

FindControl method takes string as argument, so the ("ddlvtype1" + i+1) automatically converted to string. The addition of i +1 not the type int in place of string are not the problem. The problem is I think is that "ddlvtype1" should not have the "1" at the end. Adding a number to the variable will make the control names start from 11, i.e. if i = 0, ("ddlvtype1" + i+1) = "ddlvtype11" not "ddlvtype1" what it should have been.

Maciej Los 20-Mar-13 10:13am

About FindControl:
For(){} loop starts with: ddlvtype13, because compiler "see" it as: "ddlvtype1" + Convert.ToString(2 + 1). Maybe it's not problem, but illustrate programmer's intention.
About "1" at the end:
Yes, it could be the reson of troubles, but it could be intentional...

Thank you for suggestions ;)

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Member 9671810 · Accepted Answer · 2013-03-20T06:19:00

C#

int count = Convert.ToInt16(ddlvehicles.SelectedValue);
           for (int i = 1; i <= count; i++)
           {
               cmd.Parameters.Clear();
               cmd.CommandText = "usp_booking_insert";
               cmd.CommandType = CommandType.StoredProcedure;
               cmd.Parameters.AddWithValue("@user_id", ddluname.SelectedValue);
               cmd.Parameters.AddWithValue("@journey_place", txtjplace.Text);
               cmd.Parameters.AddWithValue("@pickup_date", txtpickup_daterri.Text);
               cmd.Parameters.AddWithValue("@pickup_address", txtpickup_address.Text);
               cmd.Parameters.AddWithValue("@return_date", txtreturndate.Text);
               cmd.Parameters.AddWithValue("@return_address", txtreturn_address.Text);
               cmd.Parameters.AddWithValue("@service_id", ddlsname.SelectedValue);
               cmd.Parameters.AddWithValue("@mode_of_payment", rdbtnpayment.SelectedItem.ToString());
               int vid = Convert.ToInt16(((DropDownList)mvbooking.Views[0].FindControl("ddlvnameri" + i)).SelectedValue);
               string vtype = ((DropDownList)mvbooking.Views[0].FindControl("ddlvtype" + i)).SelectedValue;
               string vrate = ((DropDownList)mvbooking.Views[0].FindControl("ddlrate" + i)).SelectedValue;
               cmd.Parameters.AddWithValue("@vehicle_id",vid);
               cmd.Parameters.AddWithValue("@vtype_ac_nonac", vtype);
               cmd.Parameters.AddWithValue("@vrate_km_day", vrate);
           }

Thanx everyone for your co-operation.. but i solved it