using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace StudentManager.Dao
{
    /// <summary>
    ///  通用數據訪問類
    /// </summary>
    class SQLHelper
    {
        private static
 
 readonly string connString = "Server=.;DataBase=StudentManager;Uid=sa;Pwd=password01!";


        // public static readonly string connString = ConfigurationManager.ConnectionStrings["connString"].ToString();

        //private static readonly string connString =
        //    Common.StringSecurity.DESDecrypt(ConfigurationManager.ConnectionStrings["connString"].ToString());
 


        #region 執行格式化的SQL語句

        /// <summary>
        /// 執行增、刪、改（insert/update/delete）
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static int Update(string sql)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd 
 
= new SqlCommand(sql, conn);
            try
            {
                conn.Open();
                int result = cmd.ExecuteNonQuery();
                return result;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 執行單一結果查詢（select）
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static object GetSingleResult(string sql)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand(sql, conn);
            try
            {
                conn.Open();
                object result = cmd.ExecuteScalar();
                return result;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 執行多結果查詢（select）
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static SqlDataReader GetReader(string sql)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand(sql, conn);
            try
            {
                conn.Open();
                SqlDataReader objReader =
                    cmd.ExecuteReader(CommandBehavior.CloseConnection);
                return objReader;
            }
            catch (Exception ex)
            {
                conn.Close();
                throw ex;
            }
        }
        /// <summary>
        /// 執行返回數據集的查詢
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static DataSet GetDataSet(string sql)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand(sql, conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd); //創建數據適配器對象
            DataSet ds = new DataSet();//創建一個內存數據集
            try
            {
                conn.Open();
                da.Fill(ds);  //使用數據適配器填充數據集
                return ds;  //返回數據集
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                conn.Close();
            }
        }

        #endregion

        #region 帶參數的SQL語句

        public static int Update(string sql, SqlParameter[] parameter)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand(sql, conn);
            try
            {
                conn.Open();
                cmd.Parameters.AddRange(parameter);//為Command對象添加參數
                //foreach (SqlParameter  item in parameter)
                //{
                //    cmd.Parameters.Add(item);
                //}
                int result = cmd.ExecuteNonQuery();
                return result;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                conn.Close();
            }
        }

        #endregion

        #region 調用存儲過程

        public static int UpdateByProcedure(string procedureName, SqlParameter[] param)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            try
            {
                conn.Open();
                cmd.CommandType = CommandType.StoredProcedure;//聲明當前要執行的是存儲過程
                cmd.CommandText = procedureName;//commandText只需要賦值存儲過程名稱即可
                cmd.Parameters.AddRange(param);//添加存儲過程的參數
                int result = cmd.ExecuteNonQuery();
                return result;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                conn.Close();
            }
        }

        /// <summary>
        /// 執行多結果查詢（select）
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static SqlDataReader GetReaderByProcedure(string procedureName, SqlParameter[] param)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            try
            {
                conn.Open();
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.CommandText = procedureName;
                cmd.Parameters.AddRange(param);
                SqlDataReader objReader =
                    cmd.ExecuteReader(CommandBehavior.CloseConnection);
                return objReader;
            }
            catch (Exception ex)
            {
                conn.Close();
                throw ex;
            }
        }

        #endregion

        #region 啟用事務

        /// <summary>
        /// 啟用事務執行多條SQL語句
        /// </summary>      
        /// <param name="sqlList">SQL語句列表</param>      
        /// <returns></returns>
        public static bool ExecSQLByTran(List<string> sqlList)
        {
            SqlConnection conn = new SqlConnection(connString);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;

            try
            {
                conn.Open();
                cmd.Transaction = conn.BeginTransaction();   //開啟事務
                foreach (string itemSql in sqlList)//循環提交SQL語句
                {
                    cmd.CommandText = itemSql;
                    cmd.ExecuteNonQuery();
                }
                cmd.Transaction.Commit();  //提交事務(同時自動清除事務)
                return true;
            }
            catch (Exception ex)
            {
                if (cmd.Transaction != null)
                    cmd.Transaction.Rollback();//回滾事務(同時自動清除事務)
                throw new Exception("調用事務方法時出現錯誤：" + ex.Message);
            }
            finally
            {
                if (cmd.Transaction != null)
                    cmd.Transaction = null;
                conn.Close();
            }
        }

        #endregion
    }
}

SQL-sqlHelper001