SqlHelper---操做數據庫

public class SqlHelper
    {
         /// <summary>
        /// 數據庫鏈接字符串
        /// </summary>

        public static readonly string connectionString = ConfigurationManager.ConnectionStrings["xmgl"].ToString();
        // Hashtable to store cached parameters                

        #region
        /// <summary>
        ///執行一個不須要返回值的SqlCommand命令，經過指定專用的鏈接字符串。
        /// 使用參數數組形式提供參數列表 
        /// </summary>
        /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個數值表示此SqlCommand命令執行後影響的行數</returns>
        public static int ExecteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                //經過PrePareCommand方法將參數逐個加入到SqlCommand的參數集合中
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                //清空SqlCommand中的參數列表
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        ///執行一個不須要返回值的SqlCommand命令，經過指定專用的鏈接字符串。
        /// 使用參數數組形式提供參數列表 
        /// </summary>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個數值表示此SqlCommand命令執行後影響的行數</returns>
        public static int ExecteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecteNonQuery(connectionString, cmdType, cmdText, commandParameters);
        }

        /// <summary>
        ///存儲過程專用
        /// </summary>
        /// <param name="cmdText">存儲過程的名字</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個數值表示此SqlCommand命令執行後影響的行數</returns>
        public static int ExecteNonQueryProducts(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecteNonQuery(CommandType.StoredProcedure, cmdText, commandParameters);
        }

        /// <summary>
        ///Sql語句專用
        /// </summary>
        /// <param name="cmdText">T_Sql語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個數值表示此SqlCommand命令執行後影響的行數</returns>
        public static int ExecteNonQueryText(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecteNonQuery(CommandType.Text, cmdText, commandParameters);
        }

        #endregion
        #region//GetTable方法

        /// <summary>
        /// 執行一條返回結果集的SqlCommand，經過一個已經存在的數據庫鏈接
        /// 使用參數數組提供參數
        /// </summary>
        /// <param name="connecttionString">一個現有的數據庫鏈接</param>
        /// <param name="cmdTye">SqlCommand命令類型</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個表集合(DataTableCollection)表示查詢獲得的數據集</returns>
        public static DataTableCollection GetTable(string connecttionString, CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            DataSet ds = new DataSet();
            using (SqlConnection conn = new SqlConnection(connecttionString))
            {
                PrepareCommand(cmd, conn, null, cmdTye, cmdText, commandParameters);
                SqlDataAdapter adapter = new SqlDataAdapter();
                adapter.SelectCommand = cmd;
                adapter.Fill(ds);
            }
            DataTableCollection table = ds.Tables;
            return table;
        }

        /// <summary>
        /// 執行一條返回結果集的SqlCommand，經過一個已經存在的數據庫鏈接
        /// 使用參數數組提供參數
        /// </summary>
        /// <param name="cmdTye">SqlCommand命令類型</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個表集合(DataTableCollection)表示查詢獲得的數據集</returns>
        public static DataTableCollection GetTable(CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
        {
            return GetTable(cmdTye, cmdText, commandParameters);
        }


        /// <summary>
        /// 存儲過程專用
        /// </summary>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個表集合(DataTableCollection)表示查詢獲得的數據集</returns>
        public static DataTableCollection GetTableProducts(string cmdText, SqlParameter[] commandParameters)
        {
            return GetTable(CommandType.StoredProcedure, cmdText, commandParameters);
        }

        /// <summary>
        /// Sql語句專用
        /// </summary>
        /// <param name="cmdText"> T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個表集合(DataTableCollection)表示查詢獲得的數據集</returns>
        public static DataTableCollection GetTableText(string cmdText, SqlParameter[] commandParameters)
        {
            return GetTable(CommandType.Text, cmdText, commandParameters);
        }
        #endregion


        /// <summary>
        /// 爲執行命令準備參數
        /// </summary>
        /// <param name="cmd">SqlCommand 命令</param>
        /// <param name="conn">已經存在的數據庫鏈接</param>
        /// <param name="trans">數據庫事物處理</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">Command text，T-SQL語句 例如 Select * from Products</param>
        /// <param name="cmdParms">返回帶參數的命令</param>
        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {
            //判斷數據庫鏈接狀態
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            //判斷是否須要事物處理
            if (trans != null)
                cmd.Transaction = trans;
            cmd.CommandType = cmdType;
            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }

        /// <summary>
        /// Execute a SqlCommand that returns a resultset against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>A SqlDataReader containing the results</returns>
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connectionString);
            // we use a try/catch here because if the method throws an exception we want to 
            // close the connection throw code, because no datareader will exist, hence the 
            // commandBehaviour.CloseConnection will not work
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }
        #region//ExecuteDataSet方法

        /// <summary>
        /// return a dataset
        /// </summary>
        /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>return a dataset</returns>
        public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlConnection conn = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataAdapter da = new SqlDataAdapter();
                DataSet ds = new DataSet();
                da.SelectCommand = cmd;
                da.Fill(ds);
                return ds;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }


        /// <summary>
        /// 返回一個DataSet
        /// </summary>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>return a dataset</returns>
        public static DataSet ExecuteDataSet(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteDataSet(connectionString, cmdType, cmdText, commandParameters);
        }

        /// <summary>
        /// 返回一個DataSet
        /// </summary>
        /// <param name="cmdText">存儲過程的名字</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>return a dataset</returns>
        public static DataSet ExecuteDataSetProducts(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteDataSet(connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
        }

        /// <summary>
        /// 返回一個DataSet
        /// </summary>

        /// <param name="cmdText">T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>return a dataset</returns>
        public static DataSet ExecuteDataSetText(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteDataSet(connectionString, CommandType.Text, cmdText, commandParameters);
        }


        public static DataView ExecuteDataSet(string connectionString, string sortExpression, string direction, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlConnection conn = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataAdapter da = new SqlDataAdapter();
                DataSet ds = new DataSet();
                da.SelectCommand = cmd;
                da.Fill(ds);
                DataView dv = ds.Tables[0].DefaultView;
                dv.Sort = sortExpression + " " + direction;
                return dv;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }
        #endregion


        #region // ExecuteScalar方法


        /// <summary>
        /// 返回第一行的第一列
        /// </summary>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個對象</returns>
        public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteScalar(SqlHelper.connectionString, cmdType, cmdText, commandParameters);
        }

        /// <summary>
        /// 返回第一行的第一列存儲過程專用
        /// </summary>
        /// <param name="cmdText">存儲過程的名字</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個對象</returns>
        public static object ExecuteScalarProducts(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteScalar(SqlHelper.connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
        }

        /// <summary>
        /// 返回第一行的第一列Sql語句專用
        /// </summary>
        /// <param name="cmdText">者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>返回一個對象</returns>
        public static object ExecuteScalarText(string cmdText, params SqlParameter[] commandParameters)
        {
            return ExecuteScalar(SqlHelper.connectionString, CommandType.Text, cmdText, commandParameters);
        }

        /// <summary>
        /// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
        public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        /// Execute a SqlCommand that returns the first column of the first record against an existing database connection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
        /// <param name="cmdType">SqlCommand命令類型 (存儲過程， T-SQL語句， 等等。)</param>
        /// <param name="cmdText">存儲過程的名字或者 T-SQL 語句</param>
        /// <param name="commandParameters">以數組形式提供SqlCommand命令中用到的參數列表</param>
        /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
        public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            object val = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            return val;
        }

        #endregion
      
        /// <summary>
        /// 檢查是否存在
        /// </summary>
        /// <param name="strSql">Sql語句</param>
        /// <returns>bool結果</returns>
        public static bool Exists(string strSql)
        {
            int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, null));
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        /// <summary>
        /// 檢查是否存在
        /// </summary>
        /// <param name="strSql">Sql語句</param>
        /// <param name="cmdParms">參數</param>
        /// <returns>bool結果</returns>
        public static bool Exists(string strSql, params SqlParameter[] cmdParms)
        {
            int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, cmdParms));
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
    }