title: How to make database connection with oracle in delphi xe2 using TADOConnection?
body: <p>I am trying to make a database connection with Oracle using the <code>TADOConnection</code> component. I added a <code>ADOConnection1</code> to the form. Then I set the <code>Provider</code> property to "SQLOLEDB". Consider username and password of database is 111 and 222 respectively.</p>
  
  <p>Now on the <code>OnShow</code> event of the form I am trying to make the database connection.</p>
  
  <p>I have written a <code>MakeConnection</code> function called by the <code>OnShow</code> event handler:</p>
  
  <pre><code>function Tabc.MakeConnection : boolean;
  var 
    ConnString : string;
  begin
    result := false;
    try
      ADOConnection1 := TADOConnection.Create(nil);
      ADOConnection1.ConnectionString := ConnString;
      ADOConnection1.LoginPrompt := false;
      ADOConnection1.Open;
      result := true;
    except
      on E : Exception do
      begin
        exit;
      end;
    end;
  end;
  </code></pre>
  
  <p>My question is, what should be the format of the <code>ConnString</code> variable? Should I use "SQLOLEDB" as provider or anything else?</p>
  
  <p><strong>Update:</strong> </p>
  
  <p>Earlier I have created a connection to an Microsoft SQL Server whose connection string format is:</p>
  
  <pre><code>Provider=SQLNCLI10.1;Password=222;Persist Security Info=False;User ID= 111;Initial Catalog= abcde;Data Source= datasource\SQLEXPRESS;Initial File Name="";Server SPN=""
  </code></pre>