Value cannot be null. Parameter name: String

10y7.6k.NET

I got this error always and it prevents from insert to database

this is may code for error line

int id = Int32.Parse(Request.QueryString["Id"]);

the id id the column defined as auto increment with I do not need to insert to it

please help

4 Replies

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Manas Mohapatra10y ago
Accepted answer
What error you are getting when your code is executing for insert purpose. Please provide details.
+1
10y ago
thanks
I got the error in catch block which shows the inserting not complete
And when I checked the table there is no thing inserted
0
10y ago
thanks Manas
my error is fixed bu the inserting still not working
this is the code could please check it
if (!String.IsNullOrEmpty(txtContent.Text))
// Label7.Text = "Please select User Role";
//else
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
SqlCommand insert = new SqlCommand("insert into dbo.News(news, date, user) values(@News, @Date, @UserName)", conn);

Int32 id = 0;
if (Request.QueryString["Id"] != null)
{
id = Int32.Parse(Request.QueryString["Id"]);
}
// int id = Int32.Parse(Request.QueryString["Id"]);
insert.Parameters.AddWithValue("@News", txtContent.Text);
insert.Parameters.AddWithValue("@UserName", Session["Full_Name"].ToString());
insert.Parameters.AddWithValue("@Date", DateTime.Now);
try
{
conn.Open();
insert.ExecuteNonQuery();
txtContent.Text = "";

// Response.Redirect("ACourseManagement.aspx");
}
catch
{
// Label7.Visible = false;
Label10.Text = "Error when saving on database";
conn.Close();
}
}
I always got the catch exception
I appreciate that very much
+1
Manas Mohapatra10y ago
Mostly you querystringvalue is null. And when it is converting null to integer it throws you exception. So check null before your conversion like below:
Int32 id =0;

if(Request.QueryString["Id"] != null)
{
   id =Int32.Parse(Request.QueryString["Id"]);
}
+1