title: How to pass multiple parameters to the parametrized query in c# using DbParameter?
body: <p>I want to develop generalized application which can works with all type of databases (Oracle, MySQL, SQLite). So I have provide different data source to the each form from one common place. </p>
  
  <p>And I also want to use parametrized query who can accept multiple parameters. I am unable to to pass multiple parameters using DbParameter, it works fine with single parameter query but 
  not with many. </p>
  
  <p>So please help me...</p>
  
  <pre><code>            dbconnect dc = new dbconnect();//class which contain data source name
              DbConnection con;
              DbCommand cmd;
              DbDataReader dr;
              DbProviderFactory df;
              DataAdapter da;
  
              df = DbProviderFactories.GetFactory(dbconnect.dbprovider);
              con = df.CreateConnection();
              con.ConnectionString = dbconnect.sqlstr;
              con.Open();
              cmd = df.CreateCommand();
              cmd.CommandText = "update customer set" + " name='@name'," + "address='@address'," + "phone='@phone' " + "where code='@code';";
              cmd.Connection = con;
              DbDataAdapter daa = df.CreateDataAdapter();
              daa.UpdateCommand = cmd;
  
              DbParameter param = df.CreateParameter();
  
              param.ParameterName = "@name";
              param.Value = txtname.Text;
  
              param.ParameterName = "@address";
              param.Value = txtadd.Text;
  
              param.ParameterName = "@phone";
              param.Value = txtphone.Text;
  
              param.ParameterName = "@code";
              param.Value = txtcode.Text;
              daa.UpdateCommand.Parameters.Add(param);
              daa.UpdateCommand.ExecuteNonQuery();
  
              **But this not working.** 
  </code></pre>