Hoe can I merge data from two databases (oracle and SQL) in one gridview in C#

string strConnection = ConfigurationManager.ConnectionStrings["SQLConnStr"].ConnectionString;
SqlConnection sqlcon = new SqlConnection(strConnection);
SqlCommand sqlCMD = new SqlCommand();
sqlCMD.Connection = sqlcon;
sqlCMD.CommandText = " ";
SqlDataAdapter sda = new SqlDataAdapter(sqlCMD);
DataTable dt = new DataTable();
sda.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();


string connStrings1 = ConfigurationManager.ConnectionStrings["OracleConStr"].ConnectionString;
OracleConnection oclCon1 = new OracleConnection(connStrings1);
OracleCommand oclCMD1 = new OracleCommand();
oclCMD1.Connection = oclCon1;
oclCMD1.CommandText = " ";
OracleDataAdapter oda1 = new OracleDataAdapter();
oda1.SelectCommand = oclCMD1;
DataTable dt1 = new DataTable();
oda1.Fill(dt1);
GridView1.DataSource = dt1;
GridView1.DataBind();