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();
}
}
}
原文：http://www.cnblogs.com/fengdashen/p/5077015.html