System.Data.SQLite

    private SQLiteType[]    _fieldTypeArray;

    /// <summary>
    /// The behavior of the datareader
    /// </summary>
    private CommandBehavior _commandBehavior;

    /// <summary>
    /// Internal constructor, initializes the datareader and sets up to begin executing statements
    /// </summary>
    /// <param name="cmd">The SQLiteCommand this data reader is for</param>
    /// <param name="behave">The expected behavior of the data reader</param>
    internal SQLiteDataReader(SQLiteCommand cmd, CommandBehavior behave)
    {
      _command = cmd;
      _commandBehavior = behave;
      Initialize();

      if (_command != null)
        NextResult();
    }

    /// <summary>
    /// Initializes and resets the datareader's member variables
    /// </summary>
    internal void Initialize()
    {
      _activeStatementIndex = -1;
      _activeStatement = null;
      _rowsAffected = -1;
      _fieldCount = -1;
    }

    /// <returns>Returns a DbEnumerator object.</returns>
    public override Collections.IEnumerator GetEnumerator()
    {
      return new DbEnumerator(this);
    }

    /// <summary>
    /// Not implemented.  Returns 0
    /// </summary>
    public override int Depth
    {
      get
      {
        CheckClosed();
        return 0;
      }
    }

    /// <summary>
    /// Returns the number of columns in the current resultset
    /// </summary>
    public override int FieldCount
    {
      get
      {
        CheckClosed();
        return _fieldCount;

        }
      }

      throw new InvalidCastException();
    }

    /// <summary>
    /// Retrieves the column as a boolean value
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>bool</returns>
    public override bool GetBoolean(int ordinal)
    {
      VerifyType(ordinal, DbType.Boolean);
      return Convert.ToBoolean(GetValue(ordinal));
    }

    /// <summary>
    /// Retrieves the column as a single byte value
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>byte</returns>
    public override byte GetByte(int ordinal)
    {
      VerifyType(ordinal, DbType.Byte);
      return Convert.ToByte(_activeStatement._sql.GetInt32(_activeStatement, ordinal));
    }

    /// <summary>
    /// Retrieves a column as an array of bytes (blob)
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <param name="dataOffset">The zero-based index of where to begin reading the data</param>
    /// <param name="buffer">The buffer to write the bytes into</param>
    /// <param name="bufferOffset">The zero-based index of where to begin writing into the array</param>
    /// <param name="length">The number of bytes to retrieve</param>
    /// <returns>The actual number of bytes written into the array</returns>
    /// <remarks>
    /// To determine the number of bytes in the column, pass a null value for the buffer.  The total length will be returned.
    /// </remarks>
    public override long GetBytes(int ordinal, long dataOffset, byte[] buffer, int bufferOffset, int length)
    {
      VerifyType(ordinal, DbType.Binary);
      return _activeStatement._sql.GetBytes(_activeStatement, ordinal, (int)dataOffset, buffer, bufferOffset, length);
    }

    /// <summary>
    /// Returns the column as a single character
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>char</returns>
    public override char GetChar(int ordinal)
    {
      VerifyType(ordinal, DbType.SByte);
      return Convert.ToChar(_activeStatement._sql.GetInt32(_activeStatement, ordinal));
    }

    /// <summary>
    /// Retrieves a column as an array of chars (blob)
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <param name="dataOffset">The zero-based index of where to begin reading the data</param>
    /// <param name="buffer">The buffer to write the characters into</param>
    /// <param name="bufferOffset">The zero-based index of where to begin writing into the array</param>
    /// <param name="length">The number of bytes to retrieve</param>
    /// <returns>The actual number of characters written into the array</returns>
    /// <remarks>
    /// To determine the number of characters in the column, pass a null value for the buffer.  The total length will be returned.
    /// </remarks>
    public override long GetChars(int ordinal, long dataOffset, char[] buffer, int bufferOffset, int length)
    {
      VerifyType(ordinal, DbType.String);
      return _activeStatement._sql.GetChars(_activeStatement, ordinal, (int)dataOffset, buffer, bufferOffset, length);
    }

    /// <summary>
    /// Retrieves the name of the back-end datatype of the column
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>string</returns>
    public override string GetDataTypeName(int ordinal)
    {
      CheckClosed();
      SQLiteType typ = GetSQLiteType(ordinal);

      if (typ.Type == DbType.Object) return SQLiteConvert.SQLiteTypeToType(typ).Name;

      return _activeStatement._sql.ColumnType(_activeStatement, ordinal, out typ.Affinity);
    }

    /// <summary>
    /// Retrieve the column as a date/time value
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>DateTime</returns>
    public override DateTime GetDateTime(int ordinal)
    {
      VerifyType(ordinal, DbType.DateTime);
      return _activeStatement._sql.GetDateTime(_activeStatement, ordinal);
    }

    /// <summary>
    /// Retrieve the column as a decimal value
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>decimal</returns>
    public override decimal GetDecimal(int ordinal)
    {
      VerifyType(ordinal, DbType.Decimal);
      return Convert.ToDecimal(_activeStatement._sql.GetDouble(_activeStatement, ordinal));
    }

    /// <summary>
    /// Returns the column as a double
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>double</returns>
    public override double GetDouble(int ordinal)
    {
      VerifyType(ordinal, DbType.Double);
      return _activeStatement._sql.GetDouble(_activeStatement, ordinal);
    }

    /// <summary>
    /// Returns the .NET type of a given column
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>Type</returns>
    public override Type GetFieldType(int ordinal)
    {
      return SQLiteConvert.SQLiteTypeToType(GetSQLiteType(ordinal));
    }

    /// <summary>
    /// Returns a column as a float value
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>float</returns>
    public override float GetFloat(int ordinal)
    {
      VerifyType(ordinal, DbType.Single);
      return Convert.ToSingle(_activeStatement._sql.GetDouble(_activeStatement, ordinal));
    }

    /// <summary>
    /// Returns the column as a Guid
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>Guid</returns>
    public override Guid GetGuid(int ordinal)
    {
      VerifyType(ordinal, DbType.Guid);
      return new Guid(_activeStatement._sql.GetText(_activeStatement, ordinal));
    }

    /// <summary>
    /// Returns the column as a short
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>Int16</returns>
    public override Int16 GetInt16(int ordinal)
    {
      VerifyType(ordinal, DbType.Int16);
      return Convert.ToInt16(_activeStatement._sql.GetInt32(_activeStatement, ordinal));
    }

    /// <summary>
    /// Retrieves the column as an int
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>Int32</returns>
    public override Int32 GetInt32(int ordinal)
    {
      VerifyType(ordinal, DbType.Int32);
      return _activeStatement._sql.GetInt32(_activeStatement, ordinal);
    }

    /// <summary>
    /// Retrieves the column as a long
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>Int64</returns>
    public override Int64 GetInt64(int ordinal)
    {
      VerifyType(ordinal, DbType.Int64);
      return _activeStatement._sql.GetInt64(_activeStatement, ordinal);
    }

    /// <summary>
    /// Retrieves the name of the column
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>string</returns>
    public override string GetName(int ordinal)
    {
      CheckClosed();
      return _activeStatement._sql.ColumnName(_activeStatement, ordinal);
    }

    /// <summary>
    /// Retrieves the ordinal of a column, given its name
    /// </summary>
    /// <param name="name">The name of the column to retrieve</param>
    /// <returns>The int ordinal of the column</returns>
    public override int GetOrdinal(string name)
    {
      CheckClosed();
      return _activeStatement._sql.ColumnIndex(_activeStatement, name);
    }

    /// <summary>

      tbl.AcceptChanges();
      tbl.EndLoadData();

      return tbl;
    }

    /// <summary>
    /// Retrieves the column as a string
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>string</returns>
    public override string GetString(int ordinal)
    {
      VerifyType(ordinal, DbType.String);
      return _activeStatement._sql.GetText(_activeStatement, ordinal);
    }

    /// <summary>
    /// Retrieves the column as an object corresponding to the underlying datatype of the column
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>object</returns>
    public override object GetValue(int ordinal)
    {
      SQLiteType typ = GetSQLiteType(ordinal);

      return _activeStatement._sql.GetValue(_activeStatement, ordinal, ref typ);
    }

    /// <summary>
    /// Retreives the values of multiple columns, up to the size of the supplied array
    /// </summary>
    /// <param name="values">The array to fill with values from the columns in the current resultset</param>
    /// <returns>The number of columns retrieved</returns>
    public override int GetValues(object[] values)
    {
      CheckClosed();
      int nMax = _fieldCount;
      if (values.Length < nMax) nMax = values.Length;

      for (int n = 0; n < nMax; n++)
      {
        values.SetValue(GetValue(n), n);
      }

      return nMax;
    }

    /// <summary>
    /// Returns True if the resultset has rows that can be fetched
    /// </summary>
    public override bool HasRows
    {
      get
      {
        CheckClosed();
        return (_readingState != 2);
      }
    }

    /// <summary>
    /// Returns True if the data reader is closed
    /// </summary>
    public override bool IsClosed
    {
      get { return (_command == null); }
    }

    /// <summary>
    /// Returns True if the specified column is null
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>True or False</returns>
    public override bool IsDBNull(int ordinal)
    {
      CheckClosed();
      return _activeStatement._sql.IsNull(_activeStatement, ordinal);
    }

    /// <summary>
    /// Moves to the next resultset in multiple row-returning SQL command.
    /// </summary>
    /// <returns>True if the command was successful and a new resultset is available, False otherwise.</returns>
    public override bool NextResult()
    {
      CheckClosed();

      SQLiteStatement stmt;
      int fieldCount;

        _fieldCount = fieldCount;
        _fieldTypeArray = null;

        return true;
      }
    }

    /// <summary>
    /// Retrieves the SQLiteType for a given column, and caches it to avoid repetetive interop calls.
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>A SQLiteType structure</returns>
    private SQLiteType GetSQLiteType(int ordinal)
    {
      CheckClosed();
      if (_fieldTypeArray == null) _fieldTypeArray = new SQLiteType[_fieldCount];

      if (_fieldTypeArray[ordinal].Affinity == 0)
        _fieldTypeArray[ordinal].Type = SQLiteConvert.TypeNameToDbType(_activeStatement._sql.ColumnType(_activeStatement, ordinal, out _fieldTypeArray[ordinal].Affinity));
      return _fieldTypeArray[ordinal];
    }

    /// <summary>
    /// Reads the next row from the resultset
    /// </summary>
    /// <returns>True if a new row was successfully loaded and is ready for processing</returns>
    public override bool Read()
    {
      CheckClosed();

      if (_readingState == -1) // First step was already done at the NextResult() level, so don't step again, just return true.
      {
        _readingState = 0;

        _readingState = 1; // Finished reading rows
      }

      return false;
    }

    /// <summary>
    /// Retrieve the count of records affected by an update/insert command.  Only valid once the data reader is closed!
    /// </summary>
    public override int RecordsAffected
    {
      get { return _rowsAffected; }
    }

    /// <summary>
    /// Indexer to retrieve data from a column given its name
    /// </summary>
    /// <param name="name">The name of the column to retrieve data for</param>
    /// <returns>The value contained in the column</returns>
    public override object this[string name]
    {
      get { return GetValue(GetOrdinal(name)); }
    }

    /// <summary>
    /// Indexer to retrieve data from a column given its ordinal
    /// </summary>
    /// <param name="ordinal">The index of the column to retrieve</param>
    /// <returns>The value contained in the column</returns>
    public override object this[int ordinal]
    {
      get { return GetValue(ordinal); }
    }
  }
}