Db Connection

Dhaval, Its inside the System namespace itself but in .Net 4.0 version

Hi Joshua,

                   Try this solution

                            create 1 method which will return you opened connection like this.....
    

namespace DBLayer.Util
{
    public class Dbconnection
    {
        public SqlConnection getcon()
        {
            SqlConnection dbConn = null;
            try
            {
                dbConn = new SqlConnection(Properties.Settings.Default.auftragsverwaltungConnectionString.ToString());

                  dbConn.Open()
               
            }
            catch (Exception e1)
            {
             
            }
            return dbConn;
        }
    }

so when you want to open connection just call this method like below....n close connection in every context ..i mean in every method

Dbconnection dbc=new Dbconnection();

                   dbc.getCon();  //this will open connection

                   // your code here

       con.Close();

i hope this is up to your need.

Thanx,

Pravin.

Dear Amit in Singleton pattern which namespace import for The type or namespace name 'Lazy' does not exist in the namespace system.

Hallo

Thanks for the ideas. I will try it.
Joshua

I think your problem is easily solved if you understand classes and how they work and such. You can create a class to do things for the database and then use that class in many places in your program. I should say that you can create one instance of the class and then use the one instance in many places.

Also, you can create a data source and use the data source. A data source would have just one set of data (columns or fields) so I am not sure if that would help you but if it would then the data source will do most of the details for you. Look for articles in this web site about the Entity framework.

You probably can benefit from muli-tier designs. You can create a Data Access Layer (DAL) separate from the rest of your application. Look for articles about things like that.

Hi Friend,

Let me show something I'm came with to solve your problem first of all create a singleton pattern so that you can use it to create class that can have only one instance and that instance would be available everytime you use it..
Singleton:
for .Net 3.5 version:

public class Singleton where T : new() {     private LazySingleton() { }       public static T Instance     {         get { return SingletonCreator._instance.Value; }     }       class SingletonCreator     {         static SingletonCreator() { }           internal static readonly Lazy _instance = new Lazy(() => new T());     } }

For .Net 4.0:

public class Singleton where T : new()

{       private static readonly Lazy _instance = new Lazy(() => new T());       public static T Instance     {         get { return _instance.Value; }     }   }

Now you will use it thorughout your application if you want to create a singleton object for any class.
Lets see how your DB class will look like that'll manage the connection

    public class DAL     {         static SqlConnection connection;         public DAL()         {             connection = new SqlConnection();             connection.ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["myConnectionString"];         }           public DataTable GetDataTableByAdapter(string query)         {             connection.Open();              DataTable dt = new DataTable();             new SqlDataAdapter(query, connection).Fill(dt);              connection.Close();             return dt;         }        }

In this class we have a method and that method will open the connection use it and will close it before returning the final 
values.

How to use both of the above classes to utilize the single object multiple times.

  class Program     {         static void Main(string[] args)         {             DAL dal = Singleton<DAL>.Instance;
             string query = "Select * from Production.Product";             DataTable dt = dal.GetDataTableByAdapter(query);             System.Console.Read();         }      }

I hope this is something you wanna know about the connection management. If i'm not wrong.. and surprisingly i've found some great
thing while i was creating this sample for you. Will soon publish in the article section and on my blog ;)

Happy Coding!!

Hello Javeed

thank you for the answer

yes this is wat i meen. If you have some formulars, is this not the normal way to solve the problem of connection with database ?

joshua

you mean you want to create a method like this:

Class DB
{
MySqlConnection myconn;
static String connString = Properties.Settings.Default.auftragsverwaltungConnectionString;

public DB()
{
myconn = new MySqlConnection(connString);
}

public OpenConnection()
{
if (myconn is closed or myconn is not null)
{
myconn.Open();
}
}

public CloseConnection()
{
if (myconn is open or myconn is not null)
{
myconn.Close();
myconn.dispose();
}
}

}

this is not an actual code and my have errors, but just to give you an idea i have written this. Let us know.

thanks for you answer

when i create a formular i give the code

static String connString = Properties.Settings.Default.auftragsverwaltungConnectionString;
MySqlConnection myconn = new MySqlConnection(connString)

in every formular.

my question is how can i create the code once an need for all formulars ?
So i only give the command
myconn.open

Code ..
mycone.close

in the particulair forms

thanks joshua