Ishan Ishan - 5 months ago 21
MySQL Question

How to add and access connection string from web.config

I want to add connection string to connect to mysql that are define in web.config file and access the same connection in my C# code how can I do this?

Here is my code sample that run after onclick of a button to connect to database.

protected void Button2_Click(object sender, EventArgs e)
{
String a = DropDownList1.SelectedItem.Value;
String b = DropDownList3.SelectedItem.Value.PadLeft(3, '0');
String c = TextBox2.Text.PadLeft(5,'0').ToString();
String d = TextBox3.Text.ToString();
String digit = a+ b + c + d;
try
{
myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;");
myConn.Open();
//**
string sql = "select * from testcase.main where reg_no =?";
//**
OdbcCommand cmd = new OdbcCommand(sql, myConn);
//**
cmd.Parameters.AddWithValue("?", digit);
MyReader = cmd.ExecuteReader();
//**
while (MyReader.Read())
{
String f = MyReader["pet_name"].ToString();
String g = MyReader["res_name"].ToString();

Label9.Visible = true;
Label9.Text = f;

Label10.Visible = true;
Label10.Text = "VS";

//Label11.Visible = true;
Label11.Text = g;

}

MyReader.Close();
}
catch (Exception e1)
{
Response.Write(e1.ToString());
}
finally
{
if (MyReader != null && !MyReader.IsClosed)
{
MyReader.Close();
}

if (myConn != null && myConn.State == ConnectionState.Open)
{
myConn.Close();
}
}

Answer

If you know the connection string name you can use the ConnectionStrings property of the ConfigurationManager class

E.g.

using System.Configuration;
string ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString.ToString();

Where, your web.config would contain a connectionstring named ConnectionStringName