Value cannot be null. Parameter name: String

Question

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

Manas Mohapatra · Answer

What error you are getting when your code is executing for insert purpose. Please provide details.

Joma Alrzini · Answer

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

Manas Mohapatra · Answer

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 ]); }

Joma Alrzini · Answer

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