jdbc数据库连接纽带

1.JDBC编程步骤

 （1）加载驱动方法

          *Class.forName()|Class.forName().newInstance()|new DriverName()

           *实例化时自动向DriverManager注册，不需显示调用DriverManager.registerDriver

 （2）拿到连接 Connection ct = DriverManager.getConnection(url,name,password);

 （3）执行sql语句

          *通过连接创建语句，如Statement stmt = ct.createStatement();

          *执行语句ResultSet rs = stmt.executeQuery("select * from dept");  //stmt.executeUpdate()执行insert语句，执行delete语句，执行update语句

（4）循环取得结果

          while（rs.next()） {

                    rs.getString("deptno");

                   rs.getInt("deptno");//得到值

           }

（5）关闭资源 rs.close();

                         stmt.close();

                         ct.close();

2.举例如下

 public class TestJDBC {

             public static void main(String[] args) {

                         Connection conn = null;

                         Statement stmt = null;

                         Result rs = null;

              try{

                         Class.forName("com.mysql.jdbc.Driver");

                         conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/xyh1","root","1111");

                         stmt = conn.createStatement();

                         rs = stmt.executeQuery("select * from nfs");

                         while(rs.next()) {

                                  System.out.println(rs.getString("nfsno"));

                         }

          }catch(ClassNotFoundException e) {

               e.printStackTrace();

           }catch(SQLException e) {

                   e.printlnStackTrace();

            }finally {

                try{

                       if(rs != null) {

                                       rs.close();

                                       rs = null;

                       }

                      if(stmt != null) {

                         stmt.close();stmt = null;}

                      if(conn != null) {

                         conn.close();conn = null;}

                }catch(SQLException e) {

                            e.printStackTrace();

                 }

             }

             }

}