CODEWITHSUNDEEP
c#asp.net
user3080555
user3080555

Reputation: 9

update statement does not make change

i have this class that connect to my database:

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;

/// <summary>
/// Summary description for Dcon
/// </summary>
public class Dcon
{
    public SqlConnection con;
    private SqlCommand cmd = new SqlCommand();
    public SqlDataReader dr;

    public Dcon()
    {
        con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=E:\web\WebSite4\App_Data\Dbase.mdf;Integrated Security=True");
        con.Open();
        cmd.Connection = con;
    }

    public bool IUD(string sqls)
    {
        try
        {
            cmd.CommandType = CommandType.Text;
            cmd.CommandText = sqls;
            cmd.ExecuteNonQuery();
            con.Close();
            return true;
        }
        catch
        {
            return false;
        }
    }

    public bool select(string sqls)
    {
        cmd.CommandText = sqls;
        dr = cmd.ExecuteReader();
        if(dr.Read())
            return true;
        return false;
    }

}

and this code that make updtae to my database 

if (s1.IUD("UPDATE users SET fname=N'" + TextBox1.Text + "',lname=N'" + TextBox2.Text + "',uname='" + TextBox3.Text + "',password='" + pass + "' WHERE (id=" + Request.QueryString["id"]+")"))
{
    Response.Redirect("success.aspx");
}
else
{
    Response.Redirect("faild.aspx");
}

its goes to success page but its not make change to my data, my code work at insert and select staments but i dont know why its not work when i use update statment, can any one help?!

Upvotes: 0

Views: 84

Answers (1)

syed mohsin
syed mohsin

Reputation: 2938

Multiple things to consider here.
First and most important is use a variable and check what it returns to check the # of rows affected like this

int rows = cmd.ExecuteNonQuery();

If it is 0 then there is surely something wrong with your query or there is no records with your selected criteria, Nothing else can happen except these two.

Note: Your code have several issues

  • Parameterized query should be used to avoid SQL Injections
  • Dispose the object after usage

  • QueryString can be null, Check like this

    If(Request.QueryString["id"] != null)
{
   // your update code here
}

Upvotes: 1

Related Questions