C#通用Database访问类

public class Database
    {
        #region Private Var

        private DbProviderFactory factory;
        private DbConnection conn;
        private DbTransaction trans;

        private bool transFlag;

        #endregion

        #region Private Function

        private void InitFactory()
        {
            if (String.IsNullOrEmpty(this.ProviderName)) { throw new Exception("Attribute ProviderName can't be empty"); }
            if (String.IsNullOrEmpty(this.ConnectionString)) { throw new Exception("Attribute ConnectionString can't be empty"); }

            factory = DbProviderFactories.GetFactory(this.ProviderName);
            conn = factory.CreateConnection();
            conn.ConnectionString = this.ConnectionString;
        }

        #endregion

        #region Attributes

        public string ConnectionString { get; set; }

        public string ProviderName { get; set; }

        public bool GlobalTransaction { get { return transFlag; } }

        public DbProviderFactory Factory { get { return factory; } } 

        #endregion

        #region Constructor

        public Database()
        {

        }

        public Database(string connectionString)
        {
            this.ConnectionString = connectionString;
        }

        public Database(string connectionString, string providerName)
            : this(connectionString)
        {
            this.ProviderName = providerName;
            this.InitFactory();
        }

        #endregion

        #region Public Function

        #region Open & Close

        public void Open()
        {
            try
            {
                if (factory == null) { this.InitFactory(); }
                conn.Open();
            }
            catch (Exception ex) { throw ex; }
        }

        public void Close()
        {
            try { if (conn != null) { conn.Close(); } }
            catch (Exception ex) { throw ex; }
        }

        #endregion

        #region Transaction

        public void BeginTransaction()
        {
            try
            {
                this.Open();
                trans = conn.BeginTransaction(IsolationLevel.ReadCommitted);
                transFlag = true;
            }
            catch (Exception ex) { throw ex; }
            
        }

        public void CommitTransaction()
        {
            try
            {
                trans.Commit();
                transFlag = false;
            }
            catch (Exception ex) { throw ex; }
        }

        public void RollbackTransaction()
        {
            try
            {
                trans.Rollback();
                transFlag = false;
            }
            catch (Exception ex) { throw ex; }
        }

        #endregion

        #region Execute

        public int Execute(string sqlText)
        {
            return Execute(sqlText, null);
        }

        public int Execute(string sqlText, IDataParameter[] parameterArray)
        {
            return Execute(new string[] { sqlText }, new IDataParameter[][] { parameterArray });
        }

        public int Execute(string[] sqlArray, IDataParameter[][] parameterArray)
        {
            try
            {
                int resultRows = 0;
                if (sqlArray.Length != parameterArray.Length) { throw new Exception("Parameter length is inconsistent"); }
                if (conn.State != ConnectionState.Open) { conn.Open(); }
                if (!transFlag || trans == null) { trans = conn.BeginTransaction(IsolationLevel.ReadCommitted); }

                DbCommand cmd = conn.CreateCommand();
                cmd.Transaction = trans;
                for (int i = 0; i < sqlArray.Length; i++)
                {
                    if (parameterArray[i] != null) { cmd.Parameters.AddRange(parameterArray[i]); }
                    cmd.CommandText = sqlArray[i];
                    resultRows += cmd.ExecuteNonQuery();
                    cmd.Parameters.Clear();
                }
                if (!transFlag) { trans.Commit(); }
                return resultRows;
            }
            catch (Exception ex)
            {
                if (trans != null) { trans.Rollback(); }
                throw ex;
            }
            finally { if (!transFlag) { conn.Close(); trans = null; } }
        }

        #endregion

        #region DataSet

        public void DataSet(DataSet ds, string sqlText)
        {
            DataSet(ds, sqlText, null);
        }

        public void DataSet(DataSet ds, string sqlText, IDataParameter[] parameterArray)
        {
            DataSet(ds, sqlText, parameterArray, null);
        }

        public void DataSet(DataSet ds, string[] sqlArray, IDataParameter[][] parameterArray)
        {
            DataSet(ds, sqlArray, parameterArray, null);
        }

        public void DataSet(DataSet ds, string sqlText, IDataParameter[] parameterArray, string tableName)
        {
            DataSet(ds, new string[] { sqlText }, new IDataParameter[][] { parameterArray }, tableName == null ? null : new string[] { tableName });
        }

        public void DataSet(DataSet ds, string[] sqlArray, IDataParameter[][] parameterArray, string[] nameList)
        {
            try
            {
                if (parameterArray != null && sqlArray.Length != parameterArray.Length) { throw new Exception("Parameter length([sqlArray] and [parameterArray]) is inconsistent"); }
                if (nameList != null && sqlArray.Length != nameList.Length) { throw new Exception("Parameter length([sqlArray] and [nameList]) is inconsistent"); }
                if (conn.State != ConnectionState.Open) { this.Open(); }
                if (trans == null) { trans = conn.BeginTransaction(IsolationLevel.ReadCommitted); }

                DbCommand cmd = conn.CreateCommand();
                cmd.Transaction = trans;
                DbDataAdapter da = factory.CreateDataAdapter();
                da.SelectCommand = cmd;
                for (int i = 0; i < sqlArray.Length; i++)
                {
                    if (parameterArray != null && parameterArray[i] != null) { cmd.Parameters.AddRange(parameterArray[i]); }
                    cmd.CommandText = sqlArray[i];
                    string tableName = "Table" + i.ToString();
                    if (nameList != null && !String.IsNullOrEmpty(nameList[i])) { tableName = nameList[i]; }
                    da.Fill(ds, tableName);
                    cmd.Parameters.Clear();
                }

                if (!transFlag) { trans.Commit(); }
            }
            catch (Exception ex)
            {
                if (trans != null) { trans.Rollback(); }
                throw ex;
            }
            finally { if (!transFlag) { conn.Close(); trans = null; } }
        }

        #endregion

        #region Create DB Item
        public DbParameter CreateDbParameter(string parameterName, object value)
        {
            DbParameter parameter = factory.CreateParameter();
            parameter.ParameterName = parameterName;
            parameter.Value = value;
            return parameter;
        }
        #endregion

        #endregion
    }