The SqlParameterCollection only accepts non-null SqlParamete

hi me code is this

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.Sql;
using System.Data.SqlClient;

public partial class member : System.Web.UI.Page
{
public string GetConnectionString()
{

//sets the connection string from your web config file "ConnString" is the name of your Connection String

return System.Configuration.ConfigurationManager.ConnectionStrings["ing"].ConnectionString;

}
protected void Page_Load(object sender, EventArgs e)
{
}
private void ExecuteInsert(string stdid,string name,string lastname,string jens,string fathername,string kodmali,string saril,string school,string maghtae,string reshte,string paye,string address,string mobil,string stdtel,string Email,string imegstd,string anjomana,string anjomanb )
{
SqlConnection conn = new SqlConnection(GetConnectionString());
SqlCommand cmd = new SqlCommand("INSERT INTO student"+ "( stdid,name,lastname,jens,fathername,kodmali,saril,school,maghtae,reshte,paye,address,mobil,stdtel,Email,imegstd,anjomana,anjomanb )"
+
"values" + " (@stdid,@name,@lastname,@jens,@fathername,@kodmali,@saril,@school,@maghtae,@reshte,@paye,@address,@mobil,@stdtel,@Email,@imegstd,@anjomana,@anjomanb)", conn);

try
{
cmd.CommandType =
CommandType.Text;
conn.Open();

// SqlCommand cmd = new SqlCommand(sql, conn);

cmd.Parameters.Add(
new SqlParameter(@stdid, SqlDbType.VarChar, 10).Value= stdid) ;
cmd.Parameters.Add(
new SqlParameter(@name, SqlDbType.VarChar, 20).Value = name);
cmd.Parameters.Add(
new SqlParameter(@lastname, SqlDbType.VarChar, 30).Value = lastname);
cmd.Parameters.Add(
new SqlParameter(@jens, SqlDbType.VarChar, 10).Value = jens);
cmd.Parameters.Add(
new SqlParameter(@fathername, SqlDbType.VarChar, 20).Value = fathername);
cmd.Parameters.Add(
new SqlParameter(@kodmali, SqlDbType.VarChar, 10).Value = kodmali);
cmd.Parameters.Add(
new SqlParameter(@saril, SqlDbType.VarChar, 10).Value = saril);
cmd.Parameters.Add(
new SqlParameter(@school, SqlDbType.VarChar, 30).Value = school);
cmd.Parameters.Add(
new SqlParameter(@maghtae, SqlDbType.VarChar, 10).Value = maghtae);
cmd.Parameters.Add(
new SqlParameter(@reshte, SqlDbType.VarChar, 20).Value = reshte);
cmd.Parameters.Add(
new SqlParameter(@paye, SqlDbType.VarChar, 10).Value = paye);
cmd.Parameters.Add(
new SqlParameter(@address, SqlDbType.VarChar, 50).Value = address);
cmd.Parameters.Add(
new SqlParameter(@mobil, SqlDbType.VarChar, 10).Value = mobil);
cmd.Parameters.Add(
new SqlParameter(@stdtel, SqlDbType.VarChar, 10).Value = stdtel);
cmd.Parameters.Add(
new SqlParameter(@Email, SqlDbType.VarChar, 20).Value = Email);
cmd.Parameters.Add(
new SqlParameter(@imegstd, SqlDbType.Image, 20).Value = imegstd);
cmd.Parameters.Add(
new SqlParameter(@anjomana, SqlDbType.VarChar, 20).Value = anjomana);
cmd.Parameters.Add(
new SqlParameter(@anjomanb, SqlDbType.VarChar, 20).Value = anjomanb);

cmd.CommandType = CommandType.Text;
cmd.ExecuteNonQuery();
}
catch (System.Data.SqlClient.SqlException ex)
{
string msg = "Insert Error:";
msg += ex.Message;
throw new Exception(msg);
}
finally
{
conn.Close();
}
}
protected void Btn1_Click(object sender, EventArgs e)
{
}
protected void Butn2_Click(object sender, EventArgs e)
{
ExecuteInsert(Tx4.Text, Tx1.Text,Tx2.Text,DropDownList1.SelectedItem.Text,Tx6.Text,Tx3.Text,Tx5.Text,Tx7.Text,DropDownList2.SelectedItem.Text,Tx18.Text,Tx19.Text,Tx10.Text,Tx9.Text,Tx8.Text,Tx11.Text,Tx14.Text,DropDownList3.SelectedItem.Text,DropDownList4.SelectedItem.Text);
Label17.Text =
"fff";

}
}

but i see this The SqlParameterCollection only accepts non-null SqlParameteThe SqlParameterCollection only accepts non-null SqlParamete

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
That was my initial thought, Shankar, but the ExecuteInsert method is being passsed the contents of various textboxes and the selected items of dropdownlists.

I think I'm right in saying that these could be empty strings but they can't be null.

However, there will definitely be a problem passing a string to a parameter which is expecting a byte array so I still think that's the most likely reason for the error.
Shankar M13y ago
Hi Raziyeh,

It is that one of the value passed to the Parameter is null. You can try debugging it to check that the Inputs passed to the query does not contain null value.
Vulpes13y ago
My guess is that the problem lies with this line:

cmd.Parameters.Add(new SqlParameter(@imegstd, SqlDbType.Image, 20).Value = imegstd);

Although you're specifying that the parameter is an image (i.e. byte array), you're passing it a string.