multiple mssql connection string in class c#

Question

Need for my app

Have database 2017,2018,2019...I add IN every form connection string

string BSS_2017 = Properties.Settings.Default.MG_SISTEM_2017CS; string BSS_2018 = Properties.Settings.Default.MG_SISTEM_2018CS;
string BSS_2019 = Properties.Settings.Default.MG_SISTEM_2019CS;
string con;

Then in label chek value (2017,2018 or2019)

public popis()
{
InitializeComponent();
yearlabel.Text = getYear();
}

And connect

private String getGodina()
{
string value = login.godina.ToString();
return value;
}
public void PullData()
{
if (yearlabel.Text == "2017")
{
con = BSS_2019;
}
else if (yearlabel.Text == "2018")
{
con = BSS_2018;
}
else if (yearlabel.Text == "2019")
{
con = BSS_2019;
}
}

That work fine...but...I must put this in every form in my app....need help

To create some class with this value.

Help?

Amit Mohanty · Answer

Hey create a separate class for connection and use it. public class ConnectionClass { static string BSS_2017 = Properties.Settings.Default.MG_SISTEM_2017CS; static string BSS_2018 = Properties.Settings.Default.MG_SISTEM_2018CS; static string BSS_2019 = Properties.Settings.Default.MG_SISTEM_2019CS; static string con; public static string PullData( string numYear) { switch (numYear) { case "2017" : con = BSS_2017; break ; case "2018" : con = BSS_2018; break ; case "2019" : con = BSS_2019; break ; } return con; } } Then call the function where you want. string conString = ConnectionClass.PullData(yearlabel.Text);

Amit Mohanty · Answer

Hey Goran first check what you get in conString variable.

Goran Bibic · Answer

Amit Mohanty Intialize component string conString = ConnectionClass.PullData(yearlabel.Text); I put this when fill datagrid and have error Line 16 // Connection string proprerty has not intialized. private void Ulazni_racun_roba_lista_fill() { //your string string conString = ConnectionClass.PullData(godinalabel.Text); using (SqlConnection openCon = new SqlConnection(conString)) { String saveStaff = "SELECT * from dbo.popis_lista" ; Console.WriteLine(saveStaff); //Here erorr connection string proprerty has not intialized. openCon.Open(); using (SqlDataAdapter querySaveStaff = new SqlDataAdapter(saveStaff, conString)) { DataTable dt = new DataTable(); querySaveStaff.Fill(dt); PopisListaDataGridView.DataSource = dt; PopisListaDataGridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect; PopisListaDataGridView.Update(); PopisListaDataGridView.Refresh(); } } }

Goran Bibic · Answer

Rajanikant Hawaldar Yes. Need example what need to be in class?

Rajanikant Hawaldar · Answer

Create class implement singleton design pattern in class then move common code then you can accessing at all forms through class singleton instance.

Goran Bibic · Answer

Yes. But need solution...recomandition...proposal

Jaish Mathews · Answer

why can't each form derive from a base from and any connection related code move there?