JDBC获取表的主键

案例，创建订单，并根据订单号向订单明细表插入数据

sql语句：

创建两表

create table orders(

  id number(4) primary key,

  customer varchar2(20) not null,

  orderdate date default sysdate

);

create table orderDetails(

  id number(4) primary key,

  order_id number(4),

  product varchar2(50) not null,

  count number(4) not null,

  unitprice number(7,2)

);

这里核心是要使得订单的主键id = order_id

 

public void OrderInsert(){        Connection conn = null;        PreparedStatement pstmt = null;        ResultSet rs = null;                try {                        conn = DBUtils.getConnection();            //事务开始            conn.setAutoCommit(false);            //业务逻辑            //插入订单表，谁，什么时间            //插入订单明细表，上一步生产的订单号            //插入商品明细，商品单价            pstmt = conn.prepareStatement(INSERT_ORDER,                                          new String[]{"id"});//获取主键名称                        pstmt.setString(1, "威震天");            pstmt.setTimestamp(2,new java.sql.Timestamp(System.currentTimeMillis()));            pstmt.executeUpdate();            //获取ID值            rs= pstmt.getGeneratedKeys();            int orderId =0 ;            if(rs.next()){                orderId = rs.getInt(1);            }            System.out.println("order id:"+orderId);                        //事物2：            pstmt = conn.prepareStatement(INSERT_DETIAL);            pstmt.setInt(1, orderId);            pstmt.setString(2, "Cube");            pstmt.setInt(3, 10);            pstmt.setDouble(4, 5000);            pstmt.executeUpdate();            System.out.println("订单明细已插入");                                                conn.commit();                    } catch (Exception e) {            try {                conn.rollback();            } catch (SQLException sqkex) {                // TODO Auto-generated catch block                sqkex.printStackTrace();            }            e.printStackTrace();                    }finally {            try {                conn.setAutoCommit(true);                if(conn !=null)  conn.close();                } catch (SQLException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }                    }            }