关系管理系统:CustomerDaoimpl中添加用户代码add()

public void add(Customer c){
        
        Connection conn = null;
        PreparedStatement st = null;
        ResultSet rs = null;
        try{
            conn = JdbcUtils.getConnection();//工具类jdbcUtils,连接数据库,三层架构思想体现非常重要
　　　　　　　//此方法预防sql注入,采用prepareStatement ,注意SQL 代码的写法
            String sql = "insert into customer(id,name,gender,birthday,cellphone,email,preference,type,description) values(?,?,?,?,?,?,?,?,?)";
            st = conn.prepareStatement(sql); 
            st.setString(1, c.getId());
            st.setString(2, c.getName());
            st.setString(3, c.getGender());
            st.setDate(4, new java.sql.Date(c.getBirthday().getTime()));
            st.setString(5, c.getCellphone());
            st.setString(6, c.getEmail());
            st.setString(7, c.getPreference());
            st.setString(8, c.getType());
            st.setString(9, c.getDescription());
            
            st.executeUpdate();//数据库执行更新语句
            
        }catch (Exception e) {

            throw new DaoException();//自定义异常类
            
        }finally{
            JdbcUtils.release(conn, st, rs);//释放连接数据库资源
        }