SQLHelper数据库助手类C#源码VS2010

 

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


namespace DAL
{
    public class SQLHelper
    {
        private SqlConnection conn = null;
        private SqlCommand cmd = null;
        private SqlDataReader sdr = null;
        private DataSet ds = new DataSet();
        private SqlDataAdapter sda = null;
        public SQLHelper()
        {
            string connStr = @"server=webServer\SQLExpress;database=yuqing;uid=sa;pwd=hbjohnsan707";//此处改为读txt文件
            //StreamReader sr = new StreamReader("config.txt");
            //string connStr = sr.ToString();

            conn = new SqlConnection(connStr);
        }
        private SqlConnection GetConn()
        {
            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }

            return conn;
        }


        /// <summary>
        ///  该方法执行传入的SQL“增、删、改”语句或存储过程
        /// </summary>
        /// <param name="cmdText">SQL语句</param>
        /// <param name="ct">语句类型</param>
        /// <returns></returns>
        public int ExecuteNonQuery(string cmdText, CommandType ct)
        {
            ////string connStr = @"server=webServer\SQLExpress;database=yuqing;uid=sa;pwd=hbjohnsan707";
            ////SqlConnection conn = new SqlConnection(connStr);
            ////string sql = "INSERT INTO [yuqing].[dbo].[中央采用]([题目],[内容],[采用时间],[加入日期],[采用刊物]) VALUES('人民','磊品','2010-5-23','2011-5-31','信息摘报')";
            ////conn.Open();
            ////SqlCommand cmd = new SqlCommand(sql, conn);
            //SqlCommand cmd = new SqlCommand(sql, GetConn());
            //int res = cmd.ExecuteNonQuery();
            //conn.Close();
            //return res;
            int res;
            try
            {
                cmd = new SqlCommand(cmdText, GetConn());
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {

                throw ex;
            }
            finally
            {
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                }

            }

            return res;

        }
        /// <summary>
        /// 该方法执行"带参数"传入的SQL“增、删、改”语句或存储过程
        /// </summary>
        /// <param name="cmdText">SQL语句</param>
        /// <param name="paras">参数</param>
        ///  /// <param name="ct">语句类型</param>
        /// <returns></returns>
        public int ExecuteNonQuery(string cmdText, SqlParameter[] paras, CommandType ct)
        {

            int res;
            using (cmd = new SqlCommand(cmdText, GetConn()))
            {
                cmd.Parameters.AddRange(paras);
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
            }

            return res;

        }
        /// <summary>
        /// 该方法执行传入的SQL“查询”语句或存储过程
        /// </summary>
        /// <param name="cmdText">SQL语句</param>
        /// <param name="ct">语句类型</param>
        /// <returns>返回数据表--DataTable类型</returns>
        public DataTable ExecuteQuery(string cmdText, CommandType ct)
        {
            DataTable dt = new DataTable();
            //string connStr = @"server=webServer\SQLExpress;database=yuqing;uid=sa;pwd=hbjohnsan707";
            //SqlConnection conn = new SqlConnection(connStr);
            //conn.Open();
            //SqlCommand cmd = new SqlCommand(sql, conn);
            //SqlDataReader sdr = cmd.ExecuteReader();
            //dt.Load(sdr);
            //conn.Close();
            cmd = new SqlCommand(cmdText, GetConn());
            cmd.CommandType = ct;
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }
        /// <summary>
        ///  该方法执行"带参数"传入的SQL“查询”语句或存储过程
        /// </summary>
        /// <param name="cmdText">SQL语句</param>
        /// <param name="paras">参数</param>
        /// <param name="ct">语句类型</param>
        /// <returns>返回数据表--DataTable类型</returns>
        public DataTable ExecuteQuery(string cmdText, SqlParameter[] paras, CommandType ct)
        {
            DataTable dt = new DataTable();
            //string connStr = @"server=webServer\SQLExpress;database=yuqing;uid=sa;pwd=hbjohnsan707";
            //SqlConnection conn = new SqlConnection(connStr);
            //conn.Open();
            //SqlCommand cmd = new SqlCommand(sql, conn);
            //SqlDataReader sdr = cmd.ExecuteReader();
            //dt.Load(sdr);
            //conn.Close();
            cmd = new SqlCommand(cmdText, GetConn());
            cmd.Parameters.AddRange(paras);
            cmd.CommandType = ct;
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }


        /// <summary>
        /// 根据输入的SQL语句检索数据库数据
        /// </summary>
        /// <param name="cmdText">SQL语句</param>
        /// <param name="tableName">内存中表名</param>
        /// <returns></returns>
        public DataSet SelectDataBase(string cmdText, string tableName)
        {            
            sda = new SqlDataAdapter(cmdText, conn);
            ds.Clear();
            sda.Fill(ds, tableName);
            return ds;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="changedDataSet"></param>
        /// <param name="tableName"></param>
        /// <returns></returns>
        //public DataSet UpdataDataBase(string cmdText,DataSet changedDataSet, string tableName)
        //{
        //    sda = new SqlDataAdapter(cmdText,conn);
        //    sda.Update(changedDataSet, tableName);
        //    return changedDataSet;
        //}




    }


}