Conversion failed when converting the nvarchar value to data type int

Question

I am getting the error of conversion failed in my codebehind. My code is below:

using (SqlCommand cmd = new SqlCommand((tempUsertype == \"0\" ? \"Select * from t         


        

Answer 1

I guess that NgoId is an int but you're assigning a string. So this might fix it:

var p = new SqlParameter("@NgoId", SqlDbType.int).Value = int.Parse(Convert.ToString(Session["User"]));
cmd.Parameters.Add(p);

Edit: since you have commented that the session stores the username but the NgoId is an int-column you have three options:

1. change the session to store the user-id int instead of the name
2. change the column to store the username
3. select the user-id from the table where the username is stored.

I would either prefer the first or the last option.

This works if you also prefer the last approach:

string sql = "Select * from tbl_students";
if(tempUsertype != "0")
{
    sql = @"Select s.* 
            from tbl_students s 
            where s.NgoId in (Select u.NgoId 
                              from tbl_User u 
                              where u.username = @Username)";
}
using (var cmd = new SqlCommand(sql, conn))
{
    var p = new SqlParameter("@Username", SqlDbType.varchar);
    p.Value = Convert.ToString(Session["User"]);
    cmd.Parameters.Add(p);
    // ...
}

Answer 2

Try this:

cmd.Parameters.Add("@NgoId", SqlDbType.Int).Value = Convert.ToString(Session["User"]);

This will coerce the NgoId parameter to the SQL Server int data type.