Prevent Refresh in ASP.Net

Avoid Duplicate record insert on page refresh using ASP.NET

One of most common issue which many of the web developers face in their web applications, is that the duplicate records are inserted to the Database on page refresh. If the web page contains some text box and a button to submit the textbox data to the database. In that case when the user insert some data to the textbox and click on the submit button, it will save the record to the Database and then if the user refresh the web page immediately then the same record is again saved to the database as there is no unique keys that can be used to verify the existence of the data, so as to prevent the multiple insertion.

From this behavior we can definitely know that, on the page fresh the button click event is fired.

To avoid this problem we can try this method as discuss below.

On page load event save the date/time stamp in a session variable, when the page is first loaded, a Session variable is populated with the current date/time as follows:

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());
}
}

On the page's PreRender event, a ViewState variable is set to the value of the Session variable as follows:

void Page_PreRender(object obj, EventArgs e)
{
ViewState["update"] = Session["update"];
}

Then these two values are compared to each other immediately before the database INSERT command is run.

If they are equal, then the command is permitted to execute and the Session variable is updated with the current date/time, otherwise the command is bypassed as given below:

void btnSubmit_Click(object obj, EventArgs e)
{
string name = "";
string qualification = "";
if (Session["update"].ToString() == ViewState["update"].ToString())
{
if (txtName.Text != "" || txtName.Text != null)
{
name = txtName.Text.ToString();
}
if (txtQualification.Text != "" || txtQualification.Text != null)
{
qualification = txtQualification.Text.ToString();
}
//--- Insert data function should be execute here
string strSql = "INSERT INTO Testdata (Name,Qualification) VALUES ('" + name + "','" + qualification + "')";
SqlConnection ANConnection = new SqlConnection(ConnectionString);
ANConnection.Open();
SqlCommand ANCommand = new SqlCommand(strSql, ANConnection);
ANCommand.ExecuteNonQuery();
ANConnection.Close();
ANConnection.Dispose();
//--End of save data
lblMessage.Text = "Inserted Record Sucessfully
Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());
}
else
{
lblMessage.Text = "Failure – Due to Page Refresh";
txtName.Text = "";
txtQualification.Text = "";
}
}

4 Replies

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Infosoft beena11y ago
Great post. Saved a lot of time.
0
ahmed kabir12y ago
Avoid Duplicate record insert on page refresh using ASP.NET

One of most common issue which many of the web developers face in their web applications, is that the duplicate records are inserted to the Database on page refresh. If the web page contains some text box and a button to submit the textbox data to the database. In that case when the user insert some data to the textbox and click on the submit button, it will save the record to the Database and then if the user refresh the web page immediately then the same record is again saved to the database as there is no unique keys that can be used to verify the existence of the data, so as to prevent the multiple insertion.

From this behavior we can definitely know that, on the page fresh the button click event is fired.
To avoid this problem we can try this method as discuss below.

On page load event save the date/time stamp in a session variable, when the page is first loaded, a Session variable is populated with the current date/time as follows:

protected void Page_Load(object sender, EventArgs e)

{

        if (!IsPostBack)

        {

            Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());

        }

}

On the page's PreRender event, a ViewState variable is set to the value of the Session variable as follows:

void Page_PreRender(object obj, EventArgs e)

{

    ViewState["update"] = Session["update"];

}


Then these two values are compared to each other immediately before the database INSERT command is run.
If they are equal, then the command is permitted to execute and the Session variable is updated with the current date/time, otherwise the command is bypassed as given below:

void btnSubmit_Click(object obj, EventArgs e)

{

    string name = "";

    string qualification = "";





    if (Session["update"].ToString() == ViewState["update"].ToString())

    {

        if (txtName.Text != "" || txtName.Text != null)

        {

            name = txtName.Text.ToString();

        }



        if (txtQualification.Text != "" || txtQualification.Text != null)

        {

            qualification = txtQualification.Text.ToString();

        }



       //--- Insert data function should be execute here



       string strSql = "INSERT INTO Testdata (Name,Qualification) VALUES ('" + name + "','" + qualification + "')";



        SqlConnection ANConnection = new SqlConnection(ConnectionString);



        ANConnection.Open();

        SqlCommand ANCommand = new SqlCommand(strSql, ANConnection);

        ANCommand.ExecuteNonQuery();



        ANConnection.Close();

        ANConnection.Dispose();



        //--End of save data



       lblMessage.Text = "Inserted Record Sucessfully

       Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());

    }

    else

    {

        lblMessage.Text = "Failure – Due to Page Refresh";

        txtName.Text = "";

        txtQualification.Text = "";

    }

}
+1
Jignesh Trivedi12y ago
hi,

you can also redirect page after save message to any other page like grid page if any.

how you save your data? using Form post? also provide some information about technologies which is used.
0
Satyapriya Nayak12y ago
http://www.mindfiresolutions.com/Avoid-Duplicate-record-insertion-on-page-refresh-in-ASPNET-486.php
http://www.aspsnippets.com/Articles/ASP.Net---Prevent-DuplicateDouble-Inserts-when-Page-is-refreshed.aspx
http://aspalliance.com/687_Preventing_Duplicate_Record_Insertion_on_Page_Refresh
http://www.codeproject.com/Articles/6413/Stop-Refresh-after-Submitting-your-Request
http://www.dotnetvishal.com/2012/10/avoid-duplicate-record-insertion-on.html
0