System.Data.SQLite

        /// <summary>
        /// Constructs an instance of this class using the specified native
        /// value handle.
        /// </summary>
        /// <param name="pValue">
        /// The native value handle to use.
        /// </param>
        internal SQLiteValue(IntPtr pValue)
        {
            this.pValue = pValue;
        }
        #endregion

        ///////////////////////////////////////////////////////////////////////

        #region Private Methods
        /// <summary>
        /// Invalidates the native value handle, thereby preventing further
        /// access to it from this object instance.
        /// </summary>
        private void PreventNativeAccess()
        {
            pValue = IntPtr.Zero;
        }
        #endregion
















































        ///////////////////////////////////////////////////////////////////////

        #region ISQLiteNativeHandle Members
        /// <summary>
        /// Returns the underlying SQLite native handle associated with this
        /// object instance.

            Marshal.WriteIntPtr(IntPtrForOffset(pointer, offset), value);
#endif
        }
        #endregion

        ///////////////////////////////////////////////////////////////////////

        #region SQLiteValue Helper Methods
        /// <summary>
        /// Converts a logical array of native pointers to native sqlite3_value
        /// structures into a managed array of <see cref="SQLiteValue" />
        /// object instances.
        /// </summary>
        /// <param name="argc">
        /// The number of elements in the logical array of native sqlite3_value
        /// structures.
        /// </param>
        /// <param name="argv">
        /// The native pointer to the logical array of native sqlite3_value
        /// structures to convert.
        /// </param>
        /// <returns>
        /// The managed array of <see cref="SQLiteValue" /> object instances or
        /// null upon failure.
        /// </returns>
        public static SQLiteValue[] ValueArrayFromSizeAndIntPtr(
            int argc,
            IntPtr argv
            )
        {
            if (argc < 0)
                return null;

            if (argv == IntPtr.Zero)
                return null;

            SQLiteValue[] result = new SQLiteValue[argc];

            for (int index = 0, offset = 0;
                    index < result.Length;
                    index++, offset += IntPtr.Size)
            {
                IntPtr pArg = ReadIntPtr(argv, offset);

                result[index] = (pArg != IntPtr.Zero) ?
                    new SQLiteValue(pArg) : null;
            }

            return result;
        }
        #endregion

        ///////////////////////////////////////////////////////////////////////

        #region SQLiteIndex Helper Methods
        /// <summary>
        /// Converts a native pointer to a native sqlite3_index_info structure
        /// into a new <see cref="SQLiteIndex" /> object instance.
        /// </summary>
        /// <param name="pIndex">
        /// The native pointer to the native sqlite3_index_info structure to

                SQLiteVirtualTableCursor cursor = CursorFromIntPtr(
                    pVtab, pCursor);

                if (cursor != null)
                {
                    if (Filter(cursor, idxNum,
                            SQLiteString.StringFromUtf8IntPtr(idxStr),
                            SQLiteMarshal.ValueArrayFromSizeAndIntPtr(argc,
                                argv)) == SQLiteErrorCode.Ok)
                    {
                        return SQLiteErrorCode.Ok;
                    }
                }
            }
            catch (Exception e) /* NOTE: Must catch ALL. */

        {
            try
            {
                SQLiteVirtualTable table = TableFromIntPtr(pVtab);

                if (table != null)
                {
                    return Update(
                        table, SQLiteMarshal.ValueArrayFromSizeAndIntPtr(
                        argc, argv), ref rowId);
                }
            }
            catch (Exception e) /* NOTE: Must catch ALL. */
            {
                SetTableError(pVtab, e.ToString());
            }