ADO.NET 資料庫訪問對象封裝

ADO.net架構的優良使得，C#操作多數庫訪問異常方便，我們可以將驅動寫在連接字串裡，
利用 DbProviderFactory 擷取驅動的工廠，範例程式碼如下

/// <summary>/// 資料庫操作協助類，可處理CRUD 操作，和預存程序調用/// </summary>public class Dbutil{    private DbProviderFactory _factory;    private string _connectionString;    private string _connectioinName;    public string ConnectionName    {        get { return _connectioinName; }        set        {            _connectioinName = value;            _connectionString = ConfigurationManager.ConnectionStrings[value].ConnectionString;            _factory = DbProviderFactories.GetFactory(ConfigurationManager.ConnectionStrings[value].ProviderName);        }    }    public Dbutil(string connName)    {        ConnectionName = connName;    }    public DataSet ExecuteDataSet(string sql, List<DbParameter> list)    {        using (DbConnection conn = _factory.CreateConnection())        using (DbCommand cmd = _factory.CreateCommand())        using (DbDataAdapter da = _factory.CreateDataAdapter())        {            conn.ConnectionString = _connectionString;            cmd.Connection = conn;            cmd.CommandType = CommandType.Text;            cmd.CommandText = sql;            da.SelectCommand = cmd;            foreach (DbParameter i in list)            {                cmd.Parameters.Add(i);            }                       using (DataSet ds = new DataSet())            {                conn.Open();                da.Fill(ds);                return ds;            }        }    }    public int ExecuteNonQuery(string sql)    {        using (DbConnection conn = _factory.CreateConnection())        using (DbCommand cmd = _factory.CreateCommand())        {            conn.ConnectionString = _connectionString;            cmd.Connection = conn;            cmd.CommandType = CommandType.Text;            cmd.CommandText = sql;            conn.Open();                       return cmd.ExecuteNonQuery();        }    }    public int ExecuteNonQuery(string sql, List<DbParameter> list)    {        using (DbConnection conn = _factory.CreateConnection())        using (DbCommand cmd = _factory.CreateCommand())        {            conn.ConnectionString = _connectionString;            cmd.Connection = conn;            cmd.CommandType = CommandType.Text;            cmd.CommandText = sql;            foreach (DbParameter i in list)            {                cmd.Parameters.Add(i);            }            conn.Open();            return cmd.ExecuteNonQuery();        }    }    public IEnumerable<object> ExecuteProcedure(string procedureName, List<DbParameter> list)    {        using (DbConnection conn = _factory.CreateConnection())        using (DbCommand cmd = _factory.CreateCommand())        {            conn.ConnectionString = _connectionString;            cmd.Connection = conn;            cmd.CommandType = CommandType.StoredProcedure;            cmd.CommandText = procedureName;            foreach (DbParameter i in list)            {                cmd.Parameters.Add(i);            }            conn.Open();            var res = cmd.ExecuteNonQuery();            yield return res;            foreach (DbParameter i in list)            {                if (i.Direction == ParameterDirection.Output)                    yield return i.Value;            }        }    }}