获取数据库连接后，可进行增删改查操作

• 语句生成：
  Statement s = con.createStatement(sql); //生成语句
  PreparedStatement ps = (PreparedStatement) c.prepareStatement(sql); //预准备，可以填充参数
  ps.setXXX(n,value); //可以通过set来填充参数值，位置，值

• 参数查询：
  s.executeUpdate(); //执行非查询操作，增删改
  s.executeQuery(); //执行查询

Demo:

public class JDBCDAO {public static int addJDBC(JDBCModel m) throws SQLException {Connection c = DBUtil.GetConnection();// current_time() mysql内置函数，当前时间String sql = "insert jdbc (id,name,createtime) "+ "values(?,?,current_time())";PreparedStatement ps = (PreparedStatement) c.prepareStatement(sql);ps.setLong(1, 0);// 主键自增ps.setString(2, m.name);int re = 0;try {// 此处若使用execute，会返回false，但插入成功// false代表第一个执行结果的返回值不是resultsetre = ps.executeUpdate();System.out.println(re);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return re;
}public static int deleteJDBC(int i) throws SQLException {Connection c = DBUtil.GetConnection();String sql = "delete from jdbc where id=?";PreparedStatement ps = (PreparedStatement) c.prepareStatement(sql);ps.setLong(1, i);int re = 0;try {// 此处若使用execute，会返回false，但插入成功// false代表第一个执行结果的返回值不是resultsetre = ps.executeUpdate();System.out.println(re);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return re;
}public static int updateJDBC(JDBCModel m) throws SQLException {Connection c = DBUtil.GetConnection();String sql = "update jdbc set name=? where id=?";PreparedStatement ps = (PreparedStatement) c.prepareStatement(sql);ps.setString(1, m.name);ps.setLong(2, m.id);int re = 0;try {re = ps.executeUpdate();System.out.println(re);} catch (SQLException e) {e.printStackTrace();}return re;
}public static List<JDBCModel> queryJDBC() throws SQLException {List<JDBCModel> ml = new ArrayList<JDBCModel>();Connection c = DBUtil.GetConnection();String sql = "select * from jdbc  ";PreparedStatement ps = (PreparedStatement) c.prepareStatement(sql);ResultSet re = null;try {re = ps.executeQuery();} catch (SQLException e) {e.printStackTrace();}if (re != null) {while (re.next()) {JDBCModel m = new JDBCModel();m.setId(re.getInt("id"));m.setName(re.getString("name"));m.setCreatetime(re.getDate("createtime"));ml.add(m);}}return ml;
}
}