Java -- JDBC 获取数据库自动 生成的主键值

public class Demo4 {

	/*
	 create table test1
	 (
	 	id int primary key auto_increment,
	 	name varchar(20)
	 );
	 */

	@Test
	public void test1()
	{
		Connection conn = null;
		PreparedStatement st = null;
		ResultSet rs = null;
		try
		{
			conn = JdbcUtils.getConnection();
			String sql = "insert into test1(name) values(?)";
			st = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS); //默认也会返回keys
			st.setString(1, "kevin");
			st.executeUpdate();
			rs = st.getGeneratedKeys();//插入后获得主键值
			while(rs.next())
			{
				System.out.println("id: " + rs.getInt(1));
			}

		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
		finally
		{
			JdbcUtils.release(conn, st, rs);
		}
	}

	@Test
	public void test2()
	{
		Connection conn = null;
		PreparedStatement st = null;
		ResultSet rs = null;
		try
		{
			conn = JdbcUtils.getConnection();
			String sql = "select * from test1";
			st = conn.prepareStatement(sql);
			rs = st.executeQuery();
			while(rs.next())
			{
				System.out.println("id: " + rs.getInt("id"));
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
		finally
		{
			JdbcUtils.release(conn, st, rs);
		}
	}

}