jdbc native operating database

jdbc database native operating procedures:

Step: Class.forName () to load the database driver is connected;

Step Two: DriverManager.getConnection () Gets a data connection object;

Step 3: obtaining SQL sql session object, there are two ways Statement, PreparedStatement;

Step Four: SQL execution result set, before executing SQL parameter value if the parameter value set the setXXX ();

Step Five: result set is closed, close the session, the connection is closed.
Code demonstrates

String URL = "jdbc:mysql://localhost:3306/database_name";
String USER = "root";
String PASS = "123";
Connection conn = null;
Statement stat = null;//这个不能防止sql注入，需要使用PreparedStatement 
       // 注册驱动
       Class.forName("com.mysql.jdbc.Driver");
       // 创建链接
       conn = (Connection) DriverManager.getConnection(URL,USER,PASS);
       // 执行查询
       stat = conn.createStatement();
       String sql = "SELECT * FROM table_name";
       //结果集
       ResultSet rs = stat.executeQuery(sql);
       // 循环输出查询结果
       while(rs.next()){
           System.out.print(rs.getString("column_name"));
       }
    //释放资源

Long connected to the short connection

Long connection
called is connected to the presence of long duration sql transmitted to the database, typically 8 hours.
Short connection
so-called short connection is connected to the database after the operation is completed to release connection resources, but the next time they need to re-connect to the database. Such operation of the database more frequently, the performance is not very good.