cs_db.cs

此系统开发了一个公交车管理系统。系统根据权限的不同

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

namespace CarManage
{
    class cs_db
    {
        # region 返回sqldataadapter
        public static SqlDataAdapter sdaa(string cmdstring)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["sqlString"]);
            con.Open();
            SqlCommand cmd = new SqlCommand(cmdstring, con);
            SqlDataAdapter sda = new SqlDataAdapter();
            sda.SelectCommand = cmd;
            return sda;
        }
        #endregion
        #region 返回DataSet
        public static DataSet ExecuteDataSet(string cmdstring)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["sqlString"]);
            con.Open();
            SqlCommand cmd = new SqlCommand(cmdstring, con);
            SqlDataAdapter sda = new SqlDataAdapter();
            sda.SelectCommand = cmd;
            DataSet ds = new DataSet();
            sda.Fill(ds);
            return ds;
        }
        #endregion
        # region 对数据库进行无返回值操作
        public static void cmdnon(string cmdstring)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["sqlString"]);
            con.Open();
            SqlCommand cmd = new SqlCommand(cmdstring, con);
            cmd.ExecuteNonQuery();
            con.Close();
            con.Dispose();
        }
        #endregion
        # region 查询存在数量
        public static int cmdcount(string cmdstring)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["sqlString"]);
            con.Open();
            SqlCommand cmd = new SqlCommand(cmdstring, con);
            int count = Convert.ToInt32(cmd.ExecuteScalar());
            con.Close();
            con.Dispose();
            return count;
        }
        #endregion
        #region 查询单个值
        public static string findstr(string cmdstring)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["sqlString"]);
            con.Open();
            SqlCommand cmd = new SqlCommand(cmdstring, con);
            string str = Convert.ToString(cmd.ExecuteScalar());
            con.Close();
            con.Dispose();
            return str;
        }
        # endregion
    }
}