1.Oracle
private static String driver = "oracle.jdbc.driver.OracleDriver"
private static String url = "jdbc:oracle:thin:@localhost:1521:orcl"
2.Mysql
private static String driver = "com.mysql.jdbc.Driver"
private static String url = "jdbc:mysql://127.0.0.1:3306/myfirst_schema?useUnicode=true&characterEncoding=utf-8"
3.SqlServer
private static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver"
private static String url = "jdbc:sqlserver://127.0.0.1:1433;DatabaseName = employee"
