Re: Connect to my database csharp smart device - C# Discussion Boards

14-Apr-10 2:41

Hi,
I develop a charp smart device application.
I tried to connect my Formconnexion but doesn't work for me:

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;

namespace ModeDifféré
{
    public partial class Connexion : Form
    {
        public Connexion()
        {
            InitializeComponent();
        }

        private void Connexion_load(object sender, EventArgs e)
        {
            createconnexion();
        }

        private void createconnexion()
        {
            /*string chbd= Environment. + "\\BaseGmaoLocale.sdf";
            //string chcon= "Data source=\'[0]'\ BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn= new SqlCeConnection(chcon);
            sqlceconn.Open();*/
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string chcon = null;
            SqlCeCommand command;
            SqlCeDataAdapter adapter = new SqlCeDataAdapter();
            adapter.TableMappings.Add("Table", "Connexion");
            DataSet ds = new DataSet();
            string sql = null;
            string login,MotPass;
            sql = "Select login from Connexion where login=@login and MotPass=@MotPass ";
            string chcc= "BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn= new SqlCeConnection(chcc);
            sqlceconn.Open();
            try
            {
                  sqlceconn.Open();
                command = new SqlCeCommand(sql, sqlceconn);
                adapter.SelectCommand = command;
                adapter.Fill(ds, "SQL Temp Table");
                adapter.Dispose();
                command.Dispose();
                sqlceconn.Close();

                MessageBox.Show("Number of row(s) - " + ds.Tables[0].Rows.Count);
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
            if (ds.Tables[0].Rows.Count != 0)
            {
                MessageBox.Show("Authentification réussie");
                MenuP m = new MenuP();
                m.Show();
            }
            else
            {
                MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");
            }
        }
    }
}

4 notifications appears:

Warning	1	The variable 'chcon' is assigned but its value is never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	2	The variable 'login' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	3	The variable 'MotPass' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	4	The variable 'ex' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs

When running it tells me there are an error in the connexion string chcc
Can u help me
Thanks

Eddy Vluggen14-Apr-10 2:58

14-Apr-10 2:58

Tunisien86 wrote:
When running it tells me there are an error in the connexion string chcc

A connectionstring should contain more than just a filename. Start your research here[^] Smile | :)

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Tunisien8614-Apr-10 3:30

14-Apr-10 3:30

Hi,
As I read in the link u give me,I replace my string connexion by:

string chcc = "Data Source=BaseGmaoLocale.sdf;Persist Security Info=False;";

My database is a local database,when running the 4 notifications still and an sqlexception apperas:

The database file cannot be found. Check the path to the database. [ Data Source = BaseGmaoLocale.sdf ]

Any help will be useful.
Thanks

Eddy Vluggen14-Apr-10 3:34

14-Apr-10 3:34

Tunisien86 wrote:
when running the 4 notifications still

Yup. As the notifications say, you have declared variables without using them. If you don't want the notification, then remove those declarations.

Tunisien86 wrote:
and an sqlexception apperas

It's saying that it cannot find the database. You'll need to give a path + filename, or put the database-file in the current directory Smile | :)

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Tunisien8614-Apr-10 4:28

14-Apr-10 4:28

Hi,
I did as u told me like that:

string chcc = "Data Source=C:\\Users\\Admin\\Documents\\Visual Studio 2008\\Projects\\GMAOMobile\\ModeDifféré\BaseGmaoLocale.sdf;Persist Security Info=False;";

But still the same error.
Also,I don't understand u note:

put the database-file in the current directory

Thank u for u contribution

Eddy Vluggen14-Apr-10 4:48

14-Apr-10 4:48

Tunisien86 wrote:
But still the same error.

That's a location on your development-PC, whereas your application is looking in a location on your mobile device. To what path are you deploying your database? Try someting like this;

string connectionString = @"Data Source='Mobile Device\Program Files\MyApplication\Orders.sdf';"

Tunisien86 wrote:
Also,I don't understand u note:

If you don't add a path then Windows will assume the "current working directory". That's initially the location from where you started the application.

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Tunisien8614-Apr-10 4:50

14-Apr-10 4:50

Hi,
I depass the problem of the database file by adding this:

string chcc = "Data Source=C:\\Users\\Admin\\Documents\\Visual Studio 2008\\Projects\\GMAOMobile\\ModeDifféré\\BaseGmaoLocale.sdf;Persist Security Info=False;";

and also the step:

adapter.Fill(ds);

But a new sqlexception appears:

cannot found table 0

and althought the login and pasword are my database .sdf,always"can not open connection"
Help me
Thanks

Eddy Vluggen14-Apr-10 5:02

14-Apr-10 5:02

Tunisien86 wrote:
and also the step

That's a different step from your original code, which holds the line

adapter.Fill(ds, "SQL Temp Table");

Check your select-statement, or post it here.

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Tunisien8614-Apr-10 5:13

14-Apr-10 5:13

Hi,
my select statement is:

sql = "Select login from Connexion where login=@login and MotPass=@MotPass ";

Also i wanna now how to deal with the result of the

ds.Tables("Connexion").Rows.Count) - 1

Thank u

Eddy Vluggen14-Apr-10 5:29

14-Apr-10 5:29

Tunisien86 wrote:
Select login from Connexion where login=@login and MotPass=@MotPass

Doesn't this statement return NULL if the login doesn't exist? Btw, filling a dataset is a bit superfluous if you're only interested in the result of the query. There's a ExecuteScalar method that returns the first value of the first row.

Tunisien86 wrote:
Also i wanna now how to deal with the result of the

I do not understand what you are asking; that line in the original post evaluates an expression to a boolean, and takes an action based on that bool.

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Tunisien8619-Apr-10 23:02

19-Apr-10 23:02

Hi,
This is the code that solved my problem:

private void button1_Click(object sender, EventArgs e)
        {

            /*string req = "select Login, MotPasse from Connexion";
            DataTable tab = new DataTable();
            SqlCeCommand com = new SqlCeCommand(req, sqlceconn);
            SqlCeDataAdapter ada = new SqlCeDataAdapter(com);
            ada.Fill(tab);*/
            //Create the connection
            string wCS = @"Data Source =\Storage Card\ModeDifféré\BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn = new SqlCeConnection(wCS);

            //Create the command
            SqlCeCommand command = sqlceconn.CreateCommand();
            command.CommandText = "Select login from Connexion where Login=@Login and MotPasse=@MotPasse ";

            //Add the parameters
            string s1=textBox1.Text; //store the login name here YOU MUST FILL THIS IN
            SqlCeParameter Login = new SqlCeParameter("@Login", SqlDbType.NVarChar);
            Login.Value = s1;

            string s2=textBox2.Text; //store the password here YOU MUST FILL THIS IN
            SqlCeParameter MotPasse = new SqlCeParameter("@MotPasse", SqlDbType.NVarChar);
            MotPasse.Value = s2;

            command.Parameters.Add(Login);
            command.Parameters.Add(MotPasse);

            //Create the adapter
            SqlCeDataAdapter adapter = new SqlCeDataAdapter(command);

            //Create and fill the dataset
            DataSet ds = new DataSet();

            try
            {
                adapter.Fill(ds, "SQL Temp Table");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            if ((ds.Tables.Count > 0) && (ds.Tables["SQL Temp Table"] != null))
            {MessageBox.Show("Number of row(s) - " + ds.Tables["SQL Temp Table"].Rows.Count);
                if(ds.Tables["SQL Temp Table"].Rows.Count>0)
                { MessageBox.Show("Authentification réussie");
                MenuP m = new MenuP();
                m.Show();}
                else MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");}
            adapter.Dispose();
            sqlceconn.Dispose();
            command.Dispose();



        }

Thank u a lot for u contribution Smile | :)

Eddy Vluggen20-Apr-10 1:38