Why I get syntax error in this update statement? - c#

I wanted to update a table in my m/s access database where my the user entered a new password in order to replace the old one but i have syntax error in the update statement. Please help!
public partial class resetPassword : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void SubmitButton_Click(object sender, EventArgs e)
{
string userName = (string) Session["username"];
string str = #"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\inetpub\wwwroot\JetStar\database\JetstarDb.accdb";
var con = new OleDbConnection(str);
con.Open();
string pwd = Request.Form["conPassword"];
OleDbCommand cmd = new OleDbCommand("UPDATE [users] SET password = '" + pwd + "' WHERE username = '" + userName + "'", con);
try
{
cmd.ExecuteNonQuery();
MessageBox.Show("Your password has been changed successfully.");
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
finally
{
con.Close();
}
}
}

Probably this happends because password is a reserved keyword on Microsoft Access. You should use it with square brackets as [password]
But more important
You should always use parameterized queries. This kind of string concatenations are open for SQL Injection attacks.
Don't store your passwords as a plain text. Read: Best way to store password in database
Use using statement to dispose your OleDbConnection and OleDbCommand.
using(OleDbConnection con = new OleDbConnection(str))
using(OleDbCommand cmd = con.CreateCommand())
{
cmd.CommandText = "UPDATE [users] SET [password] = ? WHERE username = ?";
cmd.Parameters.Add("pass", OleDbType.VarChar).Value = pwd;
cmd.Parameters.Add("user", OleDbType.VarChar).Value = userName;
con.Open();
try
{
cmd.ExecuteNonQuery();
MessageBox.Show("Your password has been changed successfully.");
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}

92.3% (a) of all DB problems become obvious if you just print the command before you use it, and read the error message.
So replace:
OleDbCommand cmd = new OleDbCommand("UPDATE [users] SET password = '" + pwd + "' WHERE username = '" + userName + "'", con);
with something like:
String s = "UPDATE [users] SET password = '" + pwd + "' WHERE username = '" + userName + "'";
Console.WriteLine(s);
OleDbCommand cmd = new OleDbCommand(s, con);
Then post the results of:
Response.Write(ex.Message);
for all to see, and examine what it tells you very carefully.
(a) A statistic I just plucked out of nowhere - actual value may be wildly different.

Related

Invalid object name 'Main' error when inserting into Database - C# (WebForms), MySql

I know plenty of people have these issues, and I've actually tried to implement some of the suggestions to my code, however I'm getting errors that just don't make sense to me. This is my first time implementing database calls to my code. Can someone please tell me what I'm doing wrong? The following error pops up: ERROR: Invalid object name 'Main'. This is actually triggered by my exception so at least something is working. Otherwise, I don't know what the issue is. On the DB end, I have (username VARCHAR, email VARCHAR and number NCHAR) Please see the code below
static string path = Path.GetFullPath(Environment.CurrentDirectory);
static string databaseName = "u_DB.mdf";
string connectionString = #"Data Source=(localdb)\MSSQLLocalDB;AttachDbFilename=" + path + #"\" + databaseName + "; Integrated Security=True;";
private void button1_Click(object sender, EventArgs e)
{
// string query = "INSERT INTO UserInfo '" + textBox1.Text + "' and password = '" + textBox2.Text + "'";
string query = "insert into Main ([username], [email], [number]) values(#username,#email,#number)";
using (SqlConnection con = new SqlConnection(connectionString))
{
try
{
con.Open();
using (SqlCommand cmd = new SqlCommand(query, con))
{
cmd.Parameters.Add("#username", SqlDbType.VarChar).Value = textBox3.Text;
cmd.Parameters.Add("#email", SqlDbType.VarChar).Value = textBox2.Text;
cmd.Parameters.AddWithValue("#number", SqlDbType.VarChar).Value = textBox1.Text;
int rowsAdded = cmd.ExecuteNonQuery();
if (rowsAdded > 0)
MessageBox.Show("Added to Database");
else
MessageBox.Show("Nothing was added");
}
}
catch (Exception ex)
{
MessageBox.Show("ERROR: " + ex.Message);
}
con.Close();
}
}
Firstly, as Chetan assumed, do you have a main table?
The syntax of the query you are using is :
INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);
Furthermore,
AddWithValue(string parameterName, object value (<== The actual value to insert!));
in your case
AddWithValue("#number", textBox1.Text);
is enough.

MySQL Syntax Error ASP.NET

Good day!
I'm trying to figure out what error I'm having. This is the error:
And here is my code:
protected void accountGridView_RowEditing(object sender, GridViewEditEventArgs e)
{
accountGridView.EditIndex = e.NewEditIndex;
BindData();
}
protected void accountGridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
int user_id = int.Parse(accountGridView.DataKeys[e.RowIndex].Value.ToString());
TextBox txtUsername = (TextBox)accountGridView.Rows[e.RowIndex].FindControl("txtUsername");
UpdateUser(user_id, txtUsername.Text);
accountGridView.EditIndex = -1;
BindData();
}
private void UpdateUser(int user_id, string username)
{
GlobalVars cn = new GlobalVars();
MySqlConnection connection = cn.connectDB();
connection.Open();
string query = "UPDATE user SET username = '" + username + " WHERE user_id = " + user_id + "";
MySqlCommand com = new MySqlCommand(query, connection);
com.ExecuteNonQuery();
connection.Close();
}
I can't get it to work. Am I missing something here?
Any help would be much appreciated.
The error message says that you have syntax errors in your query, so the other parts(connection) are working well as expected. Now consider the query:- if you debug the program and watch the query you can see that it may look like:
UPDATE user SET username = 'asd WHERE user_id= usr_123
So what is wrong here is, You ware missed a ' after asd, need to give a pair of ' to specify the user_id(if it is a string), so the query may look like this:
string query = "UPDATE user SET username = '" + username + "' WHERE user_id = '" + user_id + "'";
But i strongly recommend you to use Parameterized queries instead for this to avoid injection. The parameterised query will looks like :
string query = "UPDATE user SET username = #username WHERE user_id = #user_id";
MySqlCommand com = new MySqlCommand(query, connection);
com.Parameters.Add("#username", MySqlDbType.VarChar).Value = username;
com.Parameters.Add("#user_id", MySqlDbType.VarChar).Value = user_id;
// execute query here

Hashed password is not recognized after changing it

I have hased my password right there on in the registration.aspx. having this code in my business layer:
public static string CreateSHAHash(string Phrase)
{
SHA512Managed HashTool = new SHA512Managed();
Byte[] PhraseAsByte = System.Text.Encoding.UTF8.GetBytes(string.Concat(Phrase));
Byte[] EncryptedBytes = HashTool.ComputeHash(PhraseAsByte);
HashTool.Clear();
return Convert.ToBase64String(EncryptedBytes);
}
and this code in the register page:
scm.Parameters.AddWithValue("#Password", BusinessLayer.ShoppingCart.CreateSHAHash(txtPW.Text));
Having the codes above, the password are being hashed in the DB and it is working fine when I log in with this code:
protected void btn_Login_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString);
conn.Open();
string checkuser = "select count(*) from UserData where Username = '" + txtUser.Text + "'";
SqlCommand scm = new SqlCommand(checkuser, conn);
int temp = Convert.ToInt32(scm.ExecuteScalar().ToString());
conn.Close();
if (temp == 1)
{
conn.Open();
string checkPassword = "select Password from UserData where Username ='" + txtUser.Text + "'";
SqlCommand passCom = new SqlCommand(checkPassword, conn);
string password = passCom.ExecuteScalar().ToString();
if (password == BusinessLayer.ShoppingCart.CreateSHAHash(txtPassword.Text))
{
Session["New"] = txtUser.Text;
Response.Write("<script>alert('Logged In')</script>");
Response.Redirect("OrderNow.aspx");
}
else
{
lblcrederror.Text = ("Credentials dont match");
}
}
else
{
lblcrederror.Text = ("Credentials dont match");
}
However when I change it having this code in my changepassword.aspx, its not letting me in with my new password.
protected void btn_update_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(conn);
con.Open();
str = "select * from UserData ";
com = new SqlCommand(str, con);
SqlDataReader reader = com.ExecuteReader();
while (reader.Read())
{
if (BusinessLayer.ShoppingCart.CreateSHAHash(txt_cpassword.Text) == reader["Password"].ToString())
{
up = 1;
}
}
reader.Close();
con.Close();
if (up == 1)
{
con.Open();
str = "update UserData set Password=#Password where UserName='" + Session["New"].ToString() + "'";
com = new SqlCommand(str, con);
com.Parameters.Add(new SqlParameter("#Password", SqlDbType.VarChar, 50));
com.Parameters["#Password"].Value = BusinessLayer.ShoppingCart.CreateSHAHash(txt_npassword.Text);
com.ExecuteNonQuery();
con.Close();
lbl_msg.Text = "Password changed Successfully";
}
else
{
lbl_msg.Text = "Please enter correct Current password";
}
}
What am I missing here?
Check if the 50 truncates the hash.
com.Parameters.Add(new SqlParameter("#Password", SqlDbType.VarChar, 50));
On a sidenote i see that your solution is very open to SQL injection.
"select Password from UserData where Username ='" + txtUser.Text + "'";
A user can write sql statements in the textbox, and hijack your database, create his own tables or drop the whole database. You should always parameterize the queries. I see that you did that to the Update statement, but you should consider doing it for all of your variables.
This quickly creates a lot of code, so i would also consider making an SQL wrapper, that wraps in all of the things you repeat. When you are done refactoring it could look something like this:
var sql = new SqlWrapper("select Password from UserData where Username = #username", txtUser.Text);
var dataSet = sql.Execute();
Then you can hide all of your connectionstring, commands++ behind this wrapper and only tell the wrapper what you actually care about.
You should also consider using a salt for your password. If you and I have the same password, the hash will be the same. A salt will fix this problem.
A good article about password security -> https://crackstation.net/hashing-security.htm

Login form doesn't accept variable characters

Initially I set both columns, username and pass, in my database(SQL Server 2012) as int in the employeeinfo table. When I entered the correct credentials, I was able to log in successfully.
However, when I changed both both columns, username and pass, to varchar(50) and entered the correct credentials, I get a message indicating username and password were incorrect.
Any idea why? Code posted below.
private void loginbutton_Click(object sender, RoutedEventArgs e)
{
SqlConnection con = new SqlConnection(ConString);
try
{
con.Open();
string query = "select * from employeeinfo where username='" +
this.txt_username.Text + "' and pass=' " +
this.txt_password.Password +"' ";
SqlCommand cmd = new SqlCommand(query, con);
cmd.ExecuteNonQuery();
SqlDataReader dr = cmd.ExecuteReader();
int count = 0;
while (dr.Read())
{
count++;
}
if (count == 1)
{
MessageBox.Show("Open Sesame!");
second sec = new second();
sec.ShowDialog();
}
if (count > 1)
{
MessageBox.Show("Note to developer: Enforce unique constraints!");
}
if (count < 1)
{
MessageBox.Show("Username and password is not correct. Please try again!");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
Try use parameters :
cmd.CommandText = "select * from employeeinfo where username=#username and pass=#pass ";
cmd.Parameters.Add("#username", SqlDbType.VarChar);
cmd.Parameters["#username"].Value = this.txt_username.Text;
cmd.Parameters.Add("#pass", SqlDbType.VarChar);
cmd.Parameters["#pass"].Value = this.txt_password.Password;
SqlDataReader sdr = cmd.ExecuteReader();
In this line you have an extra space after pass=':
string query = "select * from employeeinfo where username='"
+ this.txt_username.Text + "' and pass=' " + this.txt_password.Password +"' ";
Here is the fixed line.
string query = "select * from employeeinfo where username='"
+ this.txt_username.Text + "' and pass='" + this.txt_password.Password + "' ";
It wouldn't hurt to store your passwords more securely (hashed, not plaintext) and learn a bit about SQL injection, though. :)

Checking if a user exists, and stopping a database insert (access database)

I just don't know how to check if the users exists in the database and stop it from inserting a new row to the db (which will cause an error as I set the user to be a primary key)
protected void Button1_Click1(object sender, EventArgs e)
{
{
OleDbConnection myconnection = new OleDbConnection();
myconnection.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|Event.mdb";
myconnection.Open();
OleDbCommand myCommand = new OleDbCommand();
myCommand.Connection = myconnection;
myCommand.CommandType = CommandType.Text;
string query = string.Format("SELECT COUNT(*) FROM users WHERE uname = '{0}'");
myCommand.CommandText = query;
try
{
int amountOfUsers = (int)myCommand.ExecuteScalar();
if (amountOfUsers < 1)
{
String myQuery = "insert into users (uname,upassword,email,type) Values ('" + UserName.Text + "','" + Password.Text + "' ,'" + Email.Text + "',' user');";
myCommand.CommandText = myQuery;
myCommand.ExecuteNonQuery();
Label1.Text = "user registered";
}
else
{
Label1.Text = "user already exists";
UserName.Text = "";
Email.Text = "";
}
}
finally
{
myconnection.Close();
}
}
}
correct your query:
query = string.Format("SELECT COUNT(*) FROM users WHERE uname = '{0}'" ,UserName.Text );
Your question isn't clear at all but I can suggest a few things..
First of all, I think you forget to use your uname as a second parameter in your:
string query = string.Format("SELECT COUNT(*) FROM users WHERE uname = '{0}'");
line. You used {0} but never point any value to this parameter. (I assume you don't have a username called {0}) Like;
string query = string.Format("SELECT COUNT(*) FROM users WHERE uname = '{0}'", UserName.Text);
As a second, please always use parameterized queries. This kind of string concatenations are open for SQL Injection attakcs.
Like;
String myQuery = "insert into users (uname,upassword,email,type) Values (#uname, #upassword, #email, #type)";
OleDbCommand myCommand = new OleDbCommand(myQuery);
myCommand.Parameters.AddWithValue("#uname", UserName.Text);
myCommand.Parameters.AddWithValue("#upassword", Password.Text);
myCommand.Parameters.AddWithValue("#uname", Email.Text);
myCommand.Parameters.AddWithValue("#uname", "user");
i want to check if the username in UserName.Text is availble in the
data base or no and if it does i want to stop from inserting new data
Than you should use SELECT first to check your username is exist in your database or not like;
string query = string.Format("SELECT * FROM users WHERE uname = '{0}'", UserName.Text);
OleDbCommand myCommand = new OleDbCommand();
myCommand.CommandText = query;
SqlDataReader reader = myCommand.ExecuteReader();
if(reader.HasRows)
{
//Your username exist in your database
}
else
{
//Doesn't exist
}
you have missing the parameter uname , you have pass the text of UserName textbox to uname
for eg
"SELECT COUNT(*) FROM users WHERE uname='" + UserName.Text +"'

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