Pageload should display default values if no data in database

Question

0.00/5 (No votes)

See more:

Hi all,

I have a textbox, 2-dropdownlists and a button in my webform.

1.On Page load , if any user is selected then these textbox,dropdownlist values for that user should display from the database .I have done this and is working perfectly fine.

2. If there is no user in the database then the textbox,dropdownlist should display default values.

Please can anyone help me in doing this. I tried the 2 bit but no success.
When i tried with no values in the database its throwing error.

Thanks

C#

protected void Page_Load(object sender, EventArgs e)
        {
            
            Loaddetails();
            
        }


private void Loaddetails()
        {
            string connectionString2 = ConfigurationManager.AppSettings["Services"];
            SqlConnection myconnection2 = new SqlConnection(connectionString2);
            SqlCommand cmd2 = new SqlCommand("select TAnalysis,vendor,Biographies from Auth where Authority=@Authority");
            SqlDataReader reader2;
            cmd2.Parameters.AddWithValue("@Authority", Session["Sessionuser"]);
            cmd2.Connection = myconnection2;
            myconnection2.Open();
            reader2 = cmd2.ExecuteReader();
            reader2.Read();
            trendtxtbox.Text = (reader2["Analysis"].ToString());
            DropDownList1.Text = (reader2["vendor"].ToString());
            splitbioddl.Text = (reader2["Biographies"].ToString());
            reader2.Close();
            myconnection2.Close();
        
        }


// to insert the values on button click


 protected void saveauthbtn_Click(object sender, EventArgs e)
        {
            string connectionString = ConfigurationManager.AppSettings["Services"];
            SqlConnection myconnection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand("[sp_InsertandupdateAuthority]", myconnection);
            cmd.Parameters.AddWithValue("@Authority", Session["Sessionuser"]);
            cmd.Parameters.AddWithValue("@AuthorityName", authoritylabel.Text);
            cmd.Parameters.AddWithValue("@vendor", DropDownList1.SelectedItem.Value);
            cmd.Parameters.AddWithValue("@Biographies", splitbioddl.SelectedItem.Value);
            cmd.Parameters.AddWithValue("@Analysis", trendtxtbox.Text);
            DropDownList1.Items.Remove(DropDownList1.SelectedItem.Value);
            splitbioddl.Items.Remove(splitbioddl.SelectedItem.Value);
            trendtxtbox.Text = "";
            cmd.CommandType = CommandType.StoredProcedure;
            myconnection.Open();
            cmd.Connection = myconnection;
            cmd.ExecuteNonQuery();
            myconnection.Close();
        }

C#

protected void Page_Load(object sender, EventArgs e)
        {
            
            Loaddetails();
            
        }


 private void Loaddetails()
        {

                string connectionString2 = ConfigurationManager.AppSettings["Services"];
                SqlConnection myconnection2 = new SqlConnection(connectionString2);
                SqlCommand cmd2 = new SqlCommand("select Analysis,vendor,Biographies from Admin_Authority where Authority=@Authority");
                SqlDataReader reader2;
                cmd2.Parameters.AddWithValue("@Authority", Session["Sessionuser"]);
                cmd2.Connection = myconnection2;
                myconnection2.Open();
                reader2 = cmd2.ExecuteReader();      

                if (reader2.HasRows)//Values found in database
                {
                    reader2.Read();
                    trendtxtbox.Text = (reader2["Analysis"].ToString());
                    DropDownList1.Text = (reader2["vendor"].ToString());
                    splitbioddl.Text = (reader2["Biographies"].ToString());        

                }
                else//Populate the controls with default values
                {
                    trendtxtbox.Text = "5";
                    DropDownList1.Text = "M";
                    splitbioddl.Text = "No";
                }

                reader2.Close();
                myconnection2.Close();

            }




// to insert the values on button click


 protected void saveauthbtn_Click(object sender, EventArgs e)
        {
            string connectionString = ConfigurationManager.AppSettings["Services"];
            SqlConnection myconnection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand("[sp_InsertAdmin_Authority]", myconnection);
            cmd.Parameters.AddWithValue("@Authority", Session["Sessionuser"]);
            cmd.Parameters.AddWithValue("@AuthorityName", authoritylabel.Text);
            cmd.Parameters.AddWithValue("@vendor", DropDownList1.SelectedItem.Value);
            cmd.Parameters.AddWithValue("@Biographies", splitbioddl.SelectedItem.Value);
            cmd.Parameters.AddWithValue("@Analysis", trendtxtbox.Text);
            DropDownList1.Items.Remove(DropDownList1.SelectedItem.Value);
            splitbioddl.Items.Remove(splitbioddl.SelectedItem.Value);
            trendtxtbox.Text = "";
            cmd.CommandType = CommandType.StoredProcedure;
            myconnection.Open();
            cmd.Connection = myconnection;
            cmd.ExecuteNonQuery();
            myconnection.Close();
        }

SQL

stored procedure



ALTER PROCEDURE [dbo].[sp_InsertAdmin_Authority]
    (
      
    @Authority int ,
    @AuthorityName nvarchar(50),
    @vendor nvarchar(50),
    @Biographies nvarchar(3),
    @Analysis nvarchar(10)
    
    )
    AS

    INSERT INTO Admin_Authority
    (
      Authority,
      AuthorityName,
      vendor,
      Biographies,
      Analysis
    )
    VALUES
    (
   @Authority,
   @AuthorityName,
   @vendor,
   @Biographies,
   @Analysis
     
    )

Posted 17-Apr-13 22:23pm

babli3

Updated 18-Apr-13 0:31am

v5

Add a Solution

Comments

Zafar Sultan 18-Apr-13 4:25am

Post your code here. That will be more useful for us to figure out the error you are getting.

babli3 18-Apr-13 5:14am

I have posted my code. Thanks

Karthik Harve 18-Apr-13 4:36am

where you stuck ? where is the difficulty ?

babli3 18-Apr-13 5:16am

If there is no data in the database then these web forms should display some default values and let user insert new values.

i am not able to do this....

[no name] 18-Apr-13 4:41am

hi,
please post your code, that ll be help full

Rockstar_ 18-Apr-13 5:35am

Write condition like below...

if(trendbox.Text=="" || trendbox.Text===null) && if(othertextbox)
then assign some default value
else
{
database value
}

babli3 18-Apr-13 5:43am

HII am again getting this error

"Invalid attempt to read when no data is present"

Thanks

Rockstar_ 18-Apr-13 5:52am

Did u use solution 3 from santosh ? Use that solution with isnull function.

babli3 18-Apr-13 10:02am

yes i did

5 solutions

Solution 1

hi,

Use isnull() function in your query...

SQL

select  isnull(username,"") as uname,isnull(lastname,"") from employee

 where department='Account'

After retrieving the data check the datareader or dataset whether it has data or not...
Then based on the value retrieved you can set the textbox value..

Posted 17-Apr-13 22:35pm

Rockstar_

Updated 17-Apr-13 22:37pm

v2

Comments

babli3 18-Apr-13 5:16am

I tried using is null but isnt working

Solution 2

if No records found try this

if(count>0)
{
//here retriveing code
}
else
{
textbox1.text="Default";
ddl.ClearSelection();
ddl.datasource=null;
ddl.databind();
ddl.items.insert(0,"DefaultValue");
}

Posted 17-Apr-13 23:07pm

Sreenivasa Reddy G

Comments

babli3 18-Apr-13 5:24am

It says "The name count does not exists in the current context"

babli3 18-Apr-13 5:35am

Hi
With this code its showing the default values on pageload even if i have data in the database.

I want to show the default values on pageload only if there is no data in the databse ortherwise it shoud display values from databse.

Please help. Thank you

Solution 3

private void Loaddetails()
        {
            string connectionString2 = ConfigurationManager.AppSettings["Services"];
            SqlConnection myconnection2 = new SqlConnection(connectionString2);
            SqlCommand cmd2 = new SqlCommand("select TAnalysis,vendor,Biographies from Auth where Authority=@Authority");
            SqlDataReader reader2;
            cmd2.Parameters.AddWithValue("@Authority", Session["Sessionuser"]);
            cmd2.Connection = myconnection2;
            myconnection2.Open();
            reader2 = cmd2.ExecuteReader();
            reader2.Read();
            if(reader2["Analysis"]!=null)
            {
            trendtxtbox.Text = (reader2["Analysis"].ToString());
            }
            else
            {
                   trendtxtbox.Text = "N/A" ;
            }

            if(reader2["vendor"]!=null)
            {
                DropDownList1.Text = (reader2["vendor"].ToString());
            }
            else
            {
                   DropDownList1.Text =  "N/A" ;
            }

             
            splitbioddl.Text = (reader2["Biographies"].ToString());
            reader2.Close();
            myconnection2.Close();
        
        }

Posted 17-Apr-13 23:34pm

Santosh Kr

Comments

babli3 18-Apr-13 5:50am

HI ,
I tried this code but
I am again getting this error "Invalid attempt to read when no data is present"

Thanks

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)

Zafar Sultan · Accepted Answer · 2013-04-17T23:38:00

Solution 4

Just replace your code:

C#

reader2 = cmd2.ExecuteReader();
            reader2.Read();
            trendtxtbox.Text = (reader2["Analysis"].ToString());
            DropDownList1.Text = (reader2["vendor"].ToString());
            splitbioddl.Text = (reader2["Biographies"].ToString());

with

C#

reader2 = cmd2.ExecuteReader();
if(reader2.HasRows)//Values found in database
{
            reader2.Read();
            trendtxtbox.Text = (reader2["Analysis"].ToString());
            DropDownList1.Text = (reader2["vendor"].ToString());
            splitbioddl.Text = (reader2["Biographies"].ToString());
}
else//Populate the controls with default values
{
trendtxtbox.Text = "Your default value";
            DropDownList1.Text = "Your default value";
            splitbioddl.Text = "Your default value";
}

Posted 17-Apr-13 23:38pm

Zafar Sultan

Updated 17-Apr-13 23:40pm

v2

Comments

babli3 18-Apr-13 6:00am

Hi Zafar

Thanks the code you gave me is working for default if there is nothing in database.
But when i am trying to insert new values , its inserting the default values in the databse.

Thanks

Zafar Sultan 18-Apr-13 6:11am

The above code is for populating the controls from database. If there is no row in the database the control will be populated with the default values. Now its up to you what default values you are using to populate the controls. I just provided an example. That means else block depends totally upon your functionality. If you can elaborate further, I may be able to provide more help. And if it works for you, you can mark it as answer.

babli3 18-Apr-13 6:16am

Hi Zafar
Thanks
This code is working fine . But when I am trying to enter any values in text box or dropdown
list, its not taking those values and instead inserting the default values in the database.

Zafar Sultan 18-Apr-13 6:19am

Means? if there are no values the controls are populated with "default". But when you type or change the values of textboxes, "default" is inserted into the database? Is this the case?

babli3 18-Apr-13 6:22am

yes

Zafar Sultan 18-Apr-13 6:25am

Post your code.

babli3 18-Apr-13 6:25am

Assume my default values are 3,india
and i want to insert 5, uk

But 3, india (default values) are getting inserted into the database...thanks

Zafar Sultan 18-Apr-13 6:27am

That's why I said post the code. Without looking into it, its not possible to find out the problematic part...

babli3 18-Apr-13 6:32am

Hi
I just posted my code. Thank you

Zafar Sultan 18-Apr-13 6:37am

Replace
protected void Page_Load(object sender, EventArgs e)
{
Loaddetails();
}
with
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
Loaddetails();
}
Then In you button click event make the following change:
protected void saveauthbtn_Click(object sender, EventArgs e)
{
//your updating functionality
Loaddetails();
}

babli3 18-Apr-13 6:47am

Really sorry to bother you...

Now getting this error:

'DropDownList1' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value

Zafar Sultan 18-Apr-13 6:53am

Its OK. The reason you are getting this error is because of wrong usage of dropdownlist values both in getting and setting. By that I mean you set the value of dropdownlist by "selectedindex" or "selectedvalue" property. Similarly at the time of saving the value of dropdownlist in the database these properties are used. The following example will get you started with dropdownlist usage:
http://www.c-sharpcorner.com/UploadFile/sd_patel/DropDownListBox11222005064123AM/DropDownListBox.aspx

babli3 18-Apr-13 6:56am

Thank You...

TrushnaK · Accepted Answer · 2013-04-18T00:30:00

Solution 5

Check your reader that it has values or not using this condition:-

C#

reader2 = cmd2.ExecuteReader();

if (dr == null || !dr.HasRows)
{
     //Default values
     trendtxtbox.Text = "Val1";
     DropDownList1.Text = "Val2";
     splitbioddl.Text = "Val3";
}
else
{
     //DB Values
     trendtxtbox.Text = (reader2["Analysis"].ToString());
     DropDownList1.Text = (reader2["vendor"].ToString());
     splitbioddl.Text = (reader2["Biographies"].ToString());
}

Posted 18-Apr-13 0:30am

TrushnaK

Comments

babli3 18-Apr-13 9:09am

Hi Tushar
Thanks

The above code displays the default data on page load but , it is inserting only the default values into the database. Its not inserting the new values i m selecting.Thanks

TrushnaK 18-Apr-13 9:44am

Put this code in your Loaddetails() method. don't put it in your saveauthbtn_Click(object sender, EventArgs e)

babli3 18-Apr-13 9:51am

yes I have this in my LoadDetailsmethod(). But still its inserting the default values only.

TrushnaK 19-Apr-13 3:44am

debug your saveauthbtn_Click() Method what you get in dropdown.selected items and textboxes.Text.
I think this may get default values and you not changed that.