登录控件asp.net和CS

Question

I have a question about ASP.NET and SQL Server database and using Visual Studio 2010. The problem is about the login control cs part.

I linked my form with database, need to compare login and password with ones in DB, but the line

SqlDataReader rdr = com.ExecuteReader(); 

says that there is an error with syntax near "user"

Is it a query problem?

Can you help me please?

private bool UserLogin(string userName, string password)
{
    // read the coonection string from web.config 
    string conString = ConfigurationManager.ConnectionStrings["MidLinData"].ConnectionString;

    using (System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(conString))
    {
        con.Open();
        //' declare the command that will be used to execute the select statement 
       // SqlCommand com = new SqlCommand("SELECT login FROM user WHERE userName = @login AND Password = @password", con);
        SqlCommand com = new SqlCommand("SELECT login FROM user WHERE userName = @login ", con);
        SqlCommand com2 = new SqlCommand("SELECT password FROM user WHERE password = @password ", con);
        // set the username and password parameters
        com.Parameters.Add("@login", SqlDbType.NVarChar).Value = userName;
        SqlDataReader rdr = com.ExecuteReader();
        //com.Parameters.Add("@password", SqlDbType.NVarChar).Value = password;
        string result = rdr[0].ToString();

        // execute the select statment 
        //  string result = Convert.ToString(com.ExecuteScalar());
        //' check the result 
        if (string.IsNullOrEmpty(result))
        {
            //invalid user/password , return flase 
            return false;
        }
        else
        {
            // valid login
            return true;
        } 

        return true;
    }
}

Compiler says:

Server Error in '/visualStudioWebsite' Application.

Incorrect syntax near the keyword 'user'.

Description: An unhandled exception occurred during the execution of the current web request.

Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Incorrect syntax near the keyword 'user'.

Source Error:

Line 57: // set the username and password parameters
Line 58: com.Parameters.Add("@login", SqlDbType.NVarChar).Value = userName;
Line 59: SqlDataReader rdr = com.ExecuteReader();
Line 60: com.Parameters.Add("@password", SqlDbType.NVarChar).Value = password;
Line 61:

Source File: c:\\Users\\annasolovjova\\Desktop\\visualStudioWebsite\\login.aspx.cs Line: 59

Answer 1

You can combine both command like this:

SqlCommand com = new SqlCommand();
com.Connection = con;
com.CommandText = "SELECT login, password FROM user WHERE userName = @login and password = @password";
com.Parameters.AddWithValue("login", userName); 
com.Parameters.AddWithValue("password", password);

Answer 2

user is a reserved keyword in SQL Server - you're best bet is not to use it as a table name! And if you insist on using it, you must put it in square brackets:

SqlCommand com = new SqlCommand("SELECT login FROM [user] WHERE userName = @login ", con);