global class for DB connection

[diaafayed]

How to create a global "C#" class for data base connection such that
?
1. all classes and controls can handle.
2. remian all session untill the main from of an application closed.
3. disconnect from the server when closing windows Form application

[deceptikon]

I'd recommend against that, actually. It makes managing the connection harder. Also, many database servers will support connection pooling to eliminate the performance cost of creating, opening, and closing a connection for each transaction.

[diaafayed]

do you mean,
it is better to create connection when needed only, such that click a button or click tabpage ?

[deceptikon]

Yes.

[brite_a]

how about creating a connection in the main form/control and pass the connection details to the constructor of another.

[diaafayed]

it si a good idea, plz give us an examle that contains multiple forms and controls

[brite_a]

consider the case having an mdi parent a child form and a class for handling database connection and queries.
In the MDIParent Form, create an instance of the database class

Database DB = new Database();   /*the constructor of DB automatically opens the connection using the specified connection details.*/

Now create a child form and pass this instance to it.

        private bool CreateMdiChild(string MdiChildName, Form _form)
        {
            foreach (Form MdiChild in this.MdiChildren)
            {
                if (MdiChild.Name == MdiChildName)
                {
                    MdiChild.WindowState = FormWindowState.Normal;
                    MdiChild.BringToFront();
                    return true;
                }
            }

            Form form = _form;
            form.MdiParent = this;
            form.Show();
            return false;
        }



CreateMdiChild("NewChild", new NewChild(this.DB));

In the child form's constructor

Database DB = null;

public NewChild(Database _db)
        {
            InitializeComponent();
            DB = _db;
        }

Now you can use the old instance without creating new.