读取Oracle中的Blob字段生成对应的文件

读取Oracle中的Blob字段生成对应的文件

读取WMF的Blob字段，生成wmf文件
 /// <summary>

        /// 读取WMF字段，生成临时WMF文件

        /// </summary>

        private void ReadWMFBlobField()

        {

            OracleConnection _connection = new OracleConnection(m_connectionString);

            try

            {

                _connection.Open();

 

                OracleCommand _selectCommand = _connection.CreateCommand();

                OracleTransaction _transaction = _selectCommand.Connection.BeginTransaction();

                _selectCommand.Transaction = _transaction;

 

                string _selectSQL = "Select WMF from hSUSEr.ZDT where ZDNO = '"

                    + m_zoneNo + "'";

                _selectCommand.CommandText = _selectSQL;

 

                OracleDataReader _dataReader = _selectCommand.ExecuteReader();

                if (_dataReader.Read() == true)

                {

                    OracleLob _oracleLob = _dataReader.GetOracleLob(0);

                    long _byteCount = _oracleLob.Length;

                    _dataReader.Close();

 

                    if (File.Exists(m_wmfFileName) == true)

                    {

                        File.Delete(m_wmfFileName);

                    }

 

                    FileStream _fileStream = File.Open(m_wmfFileName, FileMode.OpenOrCreate);

                    int _length = 30485760;

                    byte[] _buffer = new byte[_length];

                    int i = _oracleLob.Read(_buffer, 0, _length);

                    while (i > 0)

                    {

                        _fileStream.Write(_buffer, 0, i);

                        i = _oracleLob.Read(_buffer, 0, _length);

                    }

 

                    _fileStream.Close();

                    _oracleLob.Close();

                    _selectCommand.Parameters.Clear();

 

                    _transaction.Commit();

                }

                else

                {

                    MessageBoxEx.Show("没有查找到相符合的记录！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

                }

            }

            catch (Exception ex)

            {

                MessageBoxEx.Show(ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);

            }

        }

读取DWG的Blob字段，生成DWG文件
 /// <summary>

        /// 读取DWG字段，生成DWG文件

        /// </summary>

        private void ReadDWGBlobField()

        {

            OracleConnection _connection = new OracleConnection(m_connectionString);

 

            try

            {

                _connection.Open();

 

                OracleCommand _selectCommand = _connection.CreateCommand();

                OracleTransaction _transaction = _selectCommand.Connection.BeginTransaction();

                _selectCommand.Transaction = _transaction;

 

                string _selectSQL = "Select DWG from hsuser.ZDT where ZDNO = '"

                    + m_zoneNo + "'";

 

                _selectCommand.CommandText = _selectSQL;

 

                OracleDataReader _dataReader = _selectCommand.ExecuteReader();

 

                if (_dataReader.Read() == true)

                {

                    OracleLob _oracleLob = _dataReader.GetOracleLob(0);

                    long _byteCount = _oracleLob.Length;

                    _dataReader.Close();

 

                    if (File.Exists(m_dwgFileName) == true)

                    {

                        File.Delete(m_dwgFileName);

                    }

 

                    FileStream _fileStream = File.Open(m_dwgFileName, FileMode.OpenOrCreate);

 

                    int _length = 30485760;

                    byte[] _buffer = new byte[_length];

                    int i;

                    while ((i = _oracleLob.Read(_buffer, 0, _length)) > 0)

                    {

                        _fileStream.Write(_buffer, 0, i);

                    }

 

                    _fileStream.Close();

                    _oracleLob.Clone();

                    _selectCommand.Parameters.Clear();

 

                    _transaction.Commit();

                }

                else

                {

                    MessageBoxEx.Show("没有查找到相符合的记录！", "提示",

                        MessageBoxButtons.OK, MessageBoxIcon.Information);

                }

            }

 

            catch (Exception ex)

            {

                MessageBoxEx.Show(ex.Message, "警告", MessageBoxButtons.OK, MessageBoxIcon.Error);

            }

        }