C#SQLServer访问接口封装，包括普通的增删改查，储存过程访问以及SQL事务。

 public class SqlHelper
    {
        //Database connection strings
        public static readonly string ConnectionStringLocal= ConfigurationManager.ConnectionStrings["SqlConnectionString"].ConnectionString;

        // Hashtable to store cached parameters
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        ///         /// 
        ///         ///         ///         ///         ///         public static int ExecuteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

            using (SqlConnection conn = new SqlConnection(ConnectionStringLocal))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        ///         /// 
        ///         ///         ///         ///         ///         ///         public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        ///         /// 
        ///         ///         ///         ///         ///         ///         public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        ///         /// 
        ///         ///         ///         ///         ///         public static SqlDataReader ExecuteReader(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(ConnectionStringLocal);

            // 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;
            }
        }

        ///         /// 执行存储过程返回值
        ///         /// 存储过程名称        /// 参数集合        /// 执行结果        public static DataTable ExecuteDataTable(string cmdText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection conn = new SqlConnection(ConnectionStringLocal))
            {
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, conn, null, CommandType.StoredProcedure, cmdText, commandParameters);
                    SqlDataAdapter da = new SqlDataAdapter();
                    DataSet ds = new DataSet();

                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    conn.Close();
                    return ds.Tables[0];
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
        }

        public static DataSet ExecuteDataSetNo(string cmdText, params SqlParameter[] commandParameters)
        {
            SqlConnection conn = new SqlConnection(ConnectionStringLocal);
            SqlCommand cmd = new SqlCommand();

            try
            {
                PrepareCommand(cmd, conn, null, CommandType.Text, cmdText, commandParameters);

                SqlDataAdapter da = new SqlDataAdapter();
                DataSet ds = new DataSet();

                da.SelectCommand = cmd;
                da.Fill(ds);

                return ds;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }

        ///         /// 执行存储过程返回值
        ///         /// 存储过程名称        /// 参数集合        /// 执行结果        public static DataTable ExecuteDataTable(CommandType cmtype, string cmdText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection conn = new SqlConnection(ConnectionStringLocal))
            {
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, conn, null, cmtype, cmdText, commandParameters);
                    SqlDataAdapter da = new SqlDataAdapter();
                    DataSet ds = new DataSet();

                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    conn.Close();
                    return ds.Tables[0];
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
        }
        ///         /// 执行存储过程返回值
        ///         /// 存储过程名称        /// 参数集合        /// 执行结果        public static DataSet ExecuteDataSet(string cmdText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection conn = new SqlConnection(ConnectionStringLocal))
            {
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, conn, null, CommandType.StoredProcedure, cmdText, commandParameters);
                    SqlDataAdapter da = new SqlDataAdapter();
                    DataSet ds = new DataSet();

                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    conn.Close();
                    return ds;
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
        }
        ///         /// 
        ///         ///         ///         ///         ///         ///         ///         public static DataView ExecuteDataSet(string sortExpression, string direction, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlConnection conn = new SqlConnection(ConnectionStringLocal);
            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;
            }
        }
        ///         /// 
        ///         ///         ///         ///         ///         public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            return NewExecuteScalar(cmdType, cmdText, commandParameters);
        }

        ///         /// 
        ///         ///         ///         ///         ///         public static object NewExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();

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

        ///         /// 
        ///         ///         ///         ///         ///         ///         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;
        }

        ///         /// 
        ///         ///         ///         public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
        {
            parmCache[cacheKey] = commandParameters;
        }

        ///         /// 
        ///         ///         ///         public static SqlParameter[] GetCachedParameters(string cacheKey)
        {
            SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        ///         /// 
        ///         /// commond对象        /// 连接对象        ///         ///         ///         ///         private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
    }