db.cs

这是一个考勤系统大家多多指教

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace kaoqin
{
    class DB
    {
        public static SqlConnection CON = new SqlConnection("server=.;database=kaoqin;uid=sa;pwd=;");
        public static string userName = "jzj";
        public static bool admin = false;
        public static DataTable getTable(string sql)
        {
            SqlDataAdapter sda = new SqlDataAdapter(sql, CON);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            return dt;
        }

        public static bool executeSql(string sql)
        {
            SqlCommand cmd = new SqlCommand(sql, CON);
            CON.Open();
            cmd.ExecuteNonQuery();
            CON.Close();
            return true;
       }

        public static string getID(string sql)
        {
            SqlCommand cmd = new SqlCommand(sql,CON);
            CON.Open();
            string id = cmd.ExecuteScalar().ToString();
            CON.Close();
            return id;
        }
    }
}